CN101850255B - Y-Sb-based composite magnetic particle optical catalyst in nuclear shell structures and application - Google Patents

Abstract

The catalytic material with the core-shell structure of the present invention has the following structural formula: γ-Fe ₂ O ₃ -Y _3-x Yb _x SbO ₇ (0.5≤x≤1), γ-Fe ₂ O ₃ -Y _3-x Ga _x SbO ₇ (0.5≤x≤1), SiO ₂ -Y _3-x Yb _x SbO ₇ (0.5≤x≤1), SiO ₂ -Y _3-x Ga _x SbO ₇ (0.5≤x≤1), MnO- Y _3-x Yb _x SbO ₇ (0.5≤x≤1) or MnO-Y _3-x Ga _x SbO ₇ (0.5≤x≤1), the particle size of γ-Fe ₂ O ₃ , SiO ₂ and MnO is 0.06 -2 microns, Y _3-x Yb _x SbO ₇ , Y _3-x Ga _x SbO ₇ coated particle size is 0.07-2.1 microns. The catalytic materials are Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x≤1). Wastewater is degraded through a reaction system composed of a magnetic field device and photocatalytic materials. The magnetic field strength is selected from 0.3 to 0.6T, and the light source is a xenon lamp or a high-pressure mercury lamp. Three kinds of catalytic materials with a core-shell structure are used to degrade wastewater in an aqueous solution. The entire light reaction was carried out in a closed and light-tight environment.

Description

Yttrium-antimony-based composite magnetic particle photocatalyst with core-shell structure and its application

technical field

The present invention relates to a new type of photocatalyst, its preparation and application, especially powder catalytic materials Y _3-x Yb _x SbO ₇ (0.5≤x≤1), Y _3-x Ga _x SbO ₇ (0.5≤x≤1) and " γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), γ-Fe ₂ O ₃ -Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1), SiO ₂ - Y _3-x Ga _x SbO ₇ (0.5≤x≤1), MnO (antiferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1), MnO-Y _3-x Ga _x SbO ₇ (0.5≤x≤1), the application of photocatalytic removal of organic pollutants in water, and the application of photocatalytic decomposition of water to produce hydrogen.

Background technique

The treatment of toxic and refractory organic substances (PTS) in water has always been a difficult and hot topic in the field of water treatment. PTS has the characteristics of high risk to human body and ecological environment. Therefore, developed countries have strict control standards for such pollutants. Since conventional biochemical treatment methods have poor removal effects (or almost no treatment effect) on such substances, special treatment unit processes must be used to remove them in a targeted manner. Therefore, the development and research of new treatment technology for refractory organic matter in water has become a hot and frontier topic in the field of international environmental engineering.

Semiconductor (typically such as TiO ₂ ) photocatalysis is recognized by scholars from all over the world as the most effective and promising technology for the treatment of refractory organic matter in water, and it has great applications in the degradation of refractory organic pollutants in water Compared with electrocatalysis and wet catalytic oxidation technology, it has obvious advantages in mineralization and decomposition of refractory organic matter. However, photocatalytic technology has not been industrialized in water treatment and wastewater treatment, and there are two main problems: (1) The photocatalytic efficiency of the suspension system photocatalytic system is high, and there is a problem of post-treatment of the catalyst. If the photocatalyst is fixed on glass and other materials It can solve the problem of separation and recovery of photocatalyst, but its photocatalytic efficiency is significantly lower than that of the suspension system; (2) titanium dioxide can only absorb ultraviolet light, has no response in the visible light range, and has a low utilization rate of sunlight (4%), while The ultraviolet part of the solar spectrum only accounts for less than 5%, while the visible light with a wavelength of 400-750nm accounts for 43% of the solar spectrum. If the ultraviolet and visible light bands in sunlight can be fully utilized at the same time, the photon quantum efficiency will increase will be greatly improved. Therefore, solving the problems of photocatalyst recovery and quantum efficiency under the premise of ensuring high photocatalytic efficiency has become the key to the industrial application of photocatalytic wastewater treatment.

At present, there are two main directions to improve the light utilization efficiency of photocatalysts. One is the visible light of titanium dioxide, such as N, S, C and other non-metallic elements partially replacing the oxygen elements in titanium dioxide, which can reduce the band gap energy of photocatalytic materials, expand its photoresponse range, and improve the photon quantum efficiency to a certain extent; The second is to research and develop highly efficient visible light catalysts. In recent years, researchers have carried out research work on exploring new visible light photocatalysts, and achieved fruitful results: Bi ₁₂ GeO ₂₀ powder can effectively degrade organic compounds such as methyl orange; Co ₃ O ₄ /BiVO ₄ can degrade phenol; ₃ N ₅ particles can degrade methylene blue dye; Na ₂ Ta ₂ O ₆ can degrade Congo red solution; Ga ₂ BiTaO ₇ can degrade methylene blue dye. Fu Xixian developed perovskite-type composite oxides LaFeO ₃ , LaFe _{1-x Cux} O _{3 ,} etc., and the results showed that LaFeO ₃ , LaFe _{1-x Cux} O ₃ (x=0.02, 0.05) had smaller band The visible light can be effectively used to photocatalytically degrade the organic matter in the water phase. Zou Zhigang and others successfully synthesized new photocatalytic materials such as CaBi ₂ O ₄ that can effectively degrade harmful substances such as formaldehyde, acetaldehyde, methylene blue and H ₂ S in water and air by using visible light. Zhu Yongfa, Zhao Jincai, etc. used self-made new materials (such as Bi ₂ WO ₆ , etc.) to quickly and effectively degrade rhodamine B in the aqueous phase, and the effect was greatly improved compared with traditional methods. For the first time, our research group successfully prepared In ₂ BiTaO ₇ powder for photocatalytic degradation of methylene blue dye in water. After 135 minutes, methylene blue was completely degraded, and the removal rate of total organic carbon (TOC) was 100%. Therefore, expanding the photoresponse range of photocatalytic materials is an effective way to improve the quantum efficiency of photocatalysis. Most of the visible light photocatalytic materials reported so far are in powder form and have good photocatalytic activity in the suspension system. Therefore, the development of new powder photocatalytic materials to remove organic pollutants in water can not only produce significant economic benefits, but also But also can produce huge environmental benefits and social benefits.

Contents of the invention

The object of the present invention is to propose a powder catalytic material Y _3-x Yb _x SbO ₇ and Y _3-x Ga _x SbO ₇ (0.5≤x≤1), its preparation process route and method, performance characterization and application. In addition, a "magnetic particle core-photocatalyst shell" structure of γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell) is also proposed , γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalytic shell), SiO ₂ (paramagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalytic shell), MnO (antiferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), MnO (antiferromagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1)( Photocatalyst shell) preparation process, performance characterization and application.

The technical solution of the present invention is: catalytic material γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell) with core-shell structure, γ- Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y _3-x Yb _x SbO ₇ ( 0.5≤x≤1) (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), MnO (antiferromagnetic particle core) -Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), MnO (antiferromagnetic particle core) -Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell ). The particle size of γ-Fe ₂ O ₃ , SiO ₂ and MnO is 0.06-2 microns, and the particle size of Y _3-x Yb _x SbO ₇ , Y _3-x Ga _x SbO ₇ is 0.07-2.1 microns.

Core-shell structured catalytic materials Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x≤1).

The preparation method is the preparation method of pulsed laser sputtering deposition:

a. Target preparation: prepare Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) targets by solid-state sintering, and the target diameter 10mm, thickness 2mm;

b. Select the substrate: use ferromagnetic particles γ-Fe ₂ O ₃ , paramagnetic particles SiO ₂ or antiferromagnetic particles MnO as the substrate;

c. Deposition by pulsed laser sputtering, the main wavelength of the laser is 248nm, the laser power density is 2-3J/cm ² , nitrogen is used as the protective atmosphere, the pressure of nitrogen and oxygen (purity is 99.99%) is 8-10Pa, the deposition chamber The initial pressure is 6×10 ^-5 Pa to 2×10 ^-3 Pa, the distance from the target to the substrate is 3 to 7 cm, and the temperature of the substrate is 300 to 700°C, respectively sputtering Y _3-x Yb _x SbO ₇ (0.5≤x≤1) targets and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) targets to ferromagnetic particles γ-Fe ₂ O ₃ , paramagnetic particles SiO ₂ or antiferromagnetic particles MnO On the surface of the substrate, films with different thicknesses are deposited on γ-Fe ₂ O ₃ , SiO ₂ or MnO substrates. The film deposition time is 90 to 120 minutes. Treat at 10°C and 1340±10°C for 60±10min to crystallize it to obtain the desired magnetic composite catalytic material γ-Fe ₂ O ₃ -Y _3-x Yb _x SbO ₇ (0.5≤x≤1), γ-Fe ₂ O ₃ -Y _3-x Ga _x SbO ₇ (0.5≤x≤1), SiO ₂ -Y _3-x Yb _x SbO ₇ (0.5≤x≤1), SiO ₂ -Y _3-x Ga _x SbO ₇ (0.5≤x≤1), MnO-Y _3-x Yb _x SbO ₇ (0.5≤x≤1), or MnO-Y _3-x Ga _x SbO ₇ (0.5≤x≤1).

Or use the method of multi-target magnetron sputtering deposition:

a. Target preparation: prepare pure metal Yb or Ga and Sb and Y metal targets, the target diameter is 5-6 cm;

b. Select the substrate: use ferromagnetic particles γ-Fe ₂ O ₃ , paramagnetic particles SiO ₂ or antiferromagnetic particles MnO as the substrate;

c. Using multi-target magnetron sputtering, the sputtering power is 60-200W, using argon as the protective atmosphere, the pressure of argon and oxygen (purity is 99.99%) is 4-32mTorr, the flow ratio of oxygen (O ₂ / (O ₂ +Ar)) is 30% to 50%, the initial pressure in the deposition chamber is 3.3×10 ^-6 Torr to 1×10 ^-5 Torr, the distance from the target to the substrate is 4 to 15 cm, and the temperature of the substrate 0～400℃, film deposition rate is 1～2nm/min;

Co-sputter pure metal Y, Yb and Sb targets in a mixed gas of oxygen and argon to the surface of ferromagnetic particles γ-Fe ₂ O ₃ , paramagnetic particles SiO ₂ or antiferromagnetic particles MnO substrate, on the substrate Deposit and form Y _3-x Yb _x SbO ₇ (0.5≤x≤1) film layer, treat the above three film layers in nitrogen or argon at 1340±10°C for 60±10min; make it crystallize to obtain the desired Photocatalyst core-shell structure γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) or MnO (antiferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1).

Co-sputter pure metal Y, Ga and Sb targets in a mixed gas of oxygen and argon to the surface of ferromagnetic particles γ-Fe ₂ O ₃ , paramagnetic particles SiO ₂ or antiferromagnetic particles MnO substrate, on the substrate Deposit and form a Y _3-x Ga _x SbO ₇ (0.5≤x≤1) film layer, and treat the above three film layers in nitrogen or argon at 1340±10°C for 60±10min; make it crystallize to obtain the desired γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) or MnO (antiferromagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1).

2. The preparation method of powder catalytic materials Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x≤1): the characteristics are (1) the powder catalytic material Y Preparation of _3-x Yb _x SbO ₇ (0.5≤x≤1) or Y _3-x Ga _x SbO ₇ (0.5≤x≤1): Y _3-x Yb _x SbO ₇ ( 0.5≤x≤1) or Y _3-x Ga _x SbO ₇ (0.5≤x≤1) photocatalytic powder material; Y ₂ O ₃ , Yb ₂ O ₃ and Sb ₂ O ₅ or Y ₂ with a purity of 99.99% O ₃ , Ga ₂ O ₃ and Sb ₂ O ₅ are raw materials, Y, Yb and Sb or Y, Ga and Sb are Y ₂ O ₃ , Yb ₂ O ₃ and Sb ₂ O ₅ or Y ₂ O ₃ , Ga ₂ O ₃ and Sb ₂ O ₅ are fully mixed, then ground in a ball mill, the particle size of the powder reaches 1.4-1.8 microns, dried at 200±40°C for 4±1 hours, pressed into tablets, put Firing in a high temperature sintering furnace. Raise the temperature of the furnace to 700±20°C, keep it warm for 8±2 hours, then cool down with the furnace, take out the pressed powder and crush it to a particle size of 1.3-1.6 microns, then press the powder into a tablet, put it into a high-temperature sintering furnace for sintering , the maximum furnace temperature is 730±20°C, keep warm for 6±1 hours and then cool with the furnace, take out the powder tablet and pulverize it to a particle size of 1.2-1.5 microns, then press the powder into a tablet, put it into a high-temperature sintering furnace for sintering , the heating conditions are as follows:

a. From 20°C to 400°C, the heating time is 40±10min; b. At 400°C for 40±10min; c. From 400°C to 730°C, the heating time is 40±10min; d. At 730°C 480-800min; e. From 730°C to 1340±50°C, the heating time is 50±10min; f. At 1340±50°C for 3800±400min, furnace cooling.

The powder tablet is kept at a maximum temperature of 1340±50°C for 3800±400min, then cooled in the furnace, the powder tablet is taken out and crushed to a particle size of 0.06-0.32 microns, and finally pure Y _3-x Yb _x SbO ₇ or Y _{3- x} Ga _x SbO ₇ (0.5≤x≤1) powder photocatalytic material;

(2) Preparation of powder photocatalytic material Y _3-x Yb _x SbO ₇ (0.5≤x≤1) or Y _3-x Ga _x SbO ₇ (0.5≤x≤1) by sol-gel method: using the improved Sol - Gel method, using organometallic precursors to prepare Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x≤1). Precursors ytterbium acetate (Yb(CH ₃ CO ₂ ) ₃ ) or gallium acetate (Ga(CH ₃ CO ₂ ) ₃ ) and yttrium acetate hydrate (Y(CH ₃ CO ₂ ) ₃ ·xH ₂ O) and antimony chloride (SbCl ₅ ) was dissolved in isopropanol, and with Y, Yb and Sb or Y, Ga and Sb in the atomic ratio of the molecular formula, using the above precursors according to the segmented sol-gel preparation method, a mixed oxide Then dry it at 200±30°C for 3±1 hours, press it into tablets, and put it into a high-temperature sintering furnace for firing. The heating conditions are as follows: a. From 20°C to 400°C, the heating time is 40±10min; b. .Insulate at 400°C for 40±10min; c.Heat from 400°C to 730°C, the heating time is 40±10min; d.Insulate at 730°C for 480-800min; 20±10min; f. Keep warm at 1050±30°C for 2200±400min, furnace cool. The powder tablet was kept at the highest temperature of 1050±30°C for 2200±400min, then cooled in the furnace, the powder tablet was taken out and crushed to a particle size of 0.04-0.20 microns, and finally pure Y _3-x Yb _x SbO ₇ (0.5≤x ≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) powder photocatalytic materials.

The beneficial effects of the present invention are: powder catalytic materials Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x ≤1), and at the same time, a novel "magnetic particle core-photocatalyst shell" structure of γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalytic shell), SiO ₂ (paramagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1), MnO (antiferromagnetic particle core) -Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), MnO (antiferromagnetic particle core) -Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell ). A series of characterizations have been carried out to study the efficiency and degradation mechanism of the above-mentioned new photocatalytic materials in degrading organic pollutants in polluted water under the irradiation of visible light or ultraviolet light, and to study the production of hydrogen by decomposing water under the irradiation of visible light or ultraviolet light. The efficiency and optical activity of the magnetic field-photocatalytic reaction system promotes the gradient distribution of the composite magnetic photocatalytic material in the organic wastewater, and also promotes the uniform distribution of the magnetic composite photocatalytic material, thereby promoting the light source and organic pollutants. The full contact with it greatly improves the degradation efficiency of organic pollutants.

Description of drawings

Figure 1A is the XRD spectrum of Y ₂ YbSbO ₇ , and Figure 1B is the XRD spectrum of Y ₂ GaSbO ₇ .

Figure 2 is the Rietveld software structural refinement map of the measured XRD data and simulated XRD data of Y ₂ YbSbO ₇ (-: XRD experimental data; ...: XRD simulated data; ---: the difference between XRD experimental data and simulated data ;|: observed reflection position).

Figure 3 is the Rietveld software structural refinement map of the measured XRD data and simulated XRD data of Y ₂ GaSbO ₇ (-: XRD experimental data; ...: XRD simulated data; ---: difference between XRD experimental data and simulated data ;|: observed reflection position).

Fig. 4 is the diffuse reflection absorption spectrum of Y ₂ YbSbO ₇ and Y ₂ GaSbO ₇ .

Fig. 5 is a graph showing the relationship between (αhv) ² and hv for Y ₂ YbSbO ₇ and Y ₂ GaSbO ₇ .

Fig. 6 is a graph showing the relationship between the absorbance and the wavelength of incident light obtained by degrading rhodamine B with Y ₂ YbSbO ₇ and Y ₂ GaSbO ₇ as catalysts under visible light irradiation.

Fig. 7 is a graph showing the relationship between Rhodamine B concentration and incident light irradiation time obtained by degrading Rhodamine B with Y ₂ YbSbO ₇ and Y ₂ GaSbO ₇ as catalysts under visible light irradiation.

Fig. 8 is a first-order kinetic curve obtained by using Y ₂ YbSbO ₇ and Y ₂ GaSbO ₇ as catalysts to degrade rhodamine B under visible light irradiation.

Fig. 9 shows the yield of CO ₂ obtained by degrading rhodamine B with Y ₂ YbSbO ₇ and Y ₂ GaSbO ₇ as catalysts under visible light irradiation.

Fig. 10 is a diagram showing the relationship between total organic carbon TOC and incident light irradiation time when Y ₂ YbSbO ₇ and Y ₂ GaSbO ₇ are used as catalysts to degrade rhodamine B under visible light irradiation.

Fig. 11 is a diagram of energy band structures of Y ₂ YbSbO ₇ and Y ₂ GaSbO ₇ .

Detailed ways

Powdered catalytic materials Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x≤1); in addition, the γ -Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), SiO ₂ ( Paramagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1), MnO (antiferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell ), MnO (antiferromagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell).

(1) Preparation of new photocatalysts Y _3-x Yb _x SbO ₇ (0.5≤x≤1), Y _3-x Ga _x SbO ₇ (0.5≤x≤1) that can respond in the visible light band or ultraviolet light band; preparation γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) with a novel "magnetic particle core-photocatalyst shell" structure capable of responding in the visible light band or ultraviolet light band (photocatalyst shell), γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalytic shell), SiO ₂ (paramagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1), MnO (antiferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell), MnO (antiferromagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1)( photocatalyst shell). The absorption spectrum of the new catalyst prepared above was measured under visible light (or ultraviolet light) irradiation by using a UV-Vis spectrophotometer and a UV-Vis diffuse reflectance spectrometer, and its light absorption properties were characterized. The X-ray photoelectron spectroscopy (XPS) of the above-mentioned new catalyst was measured, the structure characteristics of the electron layer on the surface of the above-mentioned new catalyst and the transport mechanism of electrons and holes in the catalyst crystal under the action of a magnetic field were discussed, and the catalyst supported on the surface of magnetic particles was analyzed. The elemental composition of each micro-area, and combined with the theoretical calculation results, the energy level structure and electronic density of states of the above-mentioned new catalysts were analyzed.

(2) X-ray diffractometer (XRD) was used to analyze the phase of the above-mentioned new catalyst; the microstructure characteristics of the above-mentioned new catalyst were analyzed by transmission electron microscope (TEM); Morphological analysis, combined with scanning electron microscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS), determined their composition, revealing the electronic layer structure characteristics of the new catalyst surface. It deeply reveals the influence of the microstructure of the new photocatalyst on the efficiency of photocatalytic degradation of organic pollutants.

In the process of degrading refractory organic pollutants such as dyes, atrazine or pentachlorophenol in water under the irradiation of visible light (or ultraviolet light), through liquid chromatography/mass spectrometry (LC/MS) and ion chromatography , the test tracked the intermediate products and final products in the process of degrading the above organic pollutants, and obtained the results of degrading various organic pollutants in water under the action of the new core-shell magnetic composite catalyst particles under the irradiation of visible light (or ultraviolet light). Possible pathways, revealing the degradation mechanism of organic pollutants such as dyes, atrazine or pentachlorophenol in water.

Using single-wavelength visible light (or ultraviolet light) to irradiate organic pollutants such as dyes, atrazine or pentachlorophenol in water, the photogenerated charges (photogenerated electrons or photogenerated electrons or photogenerated electrons) involved in the photocatalytic degradation reaction were successfully deduced through experimental research results and theoretical calculations. hole) number, and then deduce the number of photons of visible light (or ultraviolet light) participating in the reaction, combined with the calculated total photon number of incident light, and finally obtain the degradation of dyes and albino in water under the action of single-wavelength visible light (or ultraviolet light) Photon Quantum Efficiency of Organic Pollutants such as Trazine or Pentachlorophenol.

Table 1 Atomic structure parameters of Y ₂ YbSbO ₇

Table 2 Atomic structure parameters of Y ₂ GaSbO ₇

Detailed ways

1. The preparation process route of powder catalytic materials Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) is as follows:

(1) Preparation of powder catalytic material Y _3-x Yb _x SbO ₇ (0.5≤x≤1): Y _3-x Yb _x SbO ₇ (0.5≤x≤1) photocatalytic powder was prepared by high-temperature solid-state sintering Material. Using Y ₂ O ₃ , Yb ₂ O ₃ and Sb ₂ O ₅ with a purity of 99.99% as raw materials, Y, Yb, and Sb in the atomic ratio of Y ₂ O ₃ , Yb ₂ O ₃ and Sb ₂ O ₅ Mix well, then grind in a ball mill, the particle size of the powder reaches 1.4-1.8 microns, dry at 200±40°C for 4±1 hours, press into tablets, and put it into a high-temperature sintering furnace for firing. Raise the temperature of the furnace to 700±20°C, keep it warm for 8±2 hours, then cool down with the furnace, take out the pressed powder and crush it to a particle size of 1.3-1.6 microns, then press the powder into a tablet, put it into a high-temperature sintering furnace for sintering , the maximum furnace temperature is 730±20°C, keep warm for 6±1 hours and then cool with the furnace, take out the powder tablet and pulverize it to a particle size of 1.2-1.5 microns, then press the powder into a tablet, put it into a high-temperature sintering furnace for sintering , the heating conditions are as follows:

a. From 20°C to 400°C, the heating time is 40±10min; b. At 400°C for 40±10min; c. From 400°C to 730°C, the heating time is 40±10min; d. At 730°C 480-800min; e. From 730°C to 1340±50°C, the heating time is 50±10min; f. At 1340±50°C for 3800±400min, furnace cooling.

The powder tablet was kept at a maximum temperature of 1340±50°C for 3800±400min, then cooled in the furnace, the powder tablet was taken out and crushed to a particle size of 0.06-0.32 microns, and finally pure Y _3-x Yb _x SbO ₇ (0.5≤x ≤1) Powder photocatalytic material.

(2) Preparation of powder catalytic material Y _3-x Ga _x SbO ₇ (0.5≤x≤1): Y _3-x Ga _x SbO ₇ (0.5≤x≤1) photocatalytic powder was prepared by high-temperature solid-state sintering Material. Using Y ₂ O ₃ , Ga ₂ O 3 and Sb 2 O ₅ with a purity of 99.99% as raw _materials , Y 2 O _{3 ,} Ga ₂ O ₃ and Sb ₂ O ₅ in the atomic ratio of Y, Ga and Sb in the stated molecular formula Mix thoroughly, then grind in a ball mill, the particle size of the powder reaches 1.4-1.8 microns, dry at 200±40°C for 4±1 hours, press into tablets, and put them into a high-temperature sintering furnace for firing. Raise the temperature of the furnace to 700±20°C, keep it warm for 8±2 hours, then cool down with the furnace, take out the pressed powder and crush it to a particle size of 1.3-1.6 microns, then press the powder into a tablet, put it into a high-temperature sintering furnace for sintering , the maximum furnace temperature is 730±20°C, keep warm for 6±1 hours and then cool with the furnace, take out the powder tablet and pulverize it to a particle size of 1.2-1.5 microns, then press the powder into a tablet, put it into a high-temperature sintering furnace for sintering , the heating conditions are as follows:

a. From 20°C to 400°C, the heating time is 40±10min; b. At 400°C for 40±10min; c. From 400°C to 730°C, the heating time is 40±10min; d. At 730°C 480-800min; e. From 730°C to 1340±50°C, the heating time is 50±10min; f. At 1340±50°C for 3900±400min, furnace cooling.

The powder tablet was kept at the highest temperature of 1340±50°C for 3900±400min, then cooled in the furnace, the powder tablet was taken out and crushed to a particle size of 0.06-0.31 microns, and finally pure Y _3-x Ga _x SbO ₇ (0.5≤x ≤1) Powder photocatalytic material.

(3) Preparation of Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) by sol-gel method: change adopted by Garz-Tovar et al The Sol-Gel method uses organometallic precursors to prepare Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x≤1). Purchase precursors of ytterbium acetate (Yb(CH ₃ CO ₂ ) ₃ ), gallium acetate (Ga(CH ₃ CO ₂ ) ₃ ), yttrium acetate hydrate (Y(CH ₃ CO ₂ ) ₃ ·xH ₂ O), chloride Antimony (SbCl ₅ ) was dissolved in isopropanol, and mixed oxides were prepared by using the above precursors according to the segmented sol-gel preparation method, and then dried at 200±30°C for 3±1 hours, pressed into tablets, and placed Into the high-temperature sintering furnace for firing, the heating conditions are as follows:.

a. From 20°C to 400°C, the heating time is 40±10min; b. At 400°C for 40±10min; c. From 400°C to 730°C, the heating time is 40±10min; d. At 730°C 480-800min; e. From 730°C to 1050±30°C, the heating time is 20±10min; f. At 1050±30°C for 2200±400min, furnace cooling. The powder tablet was kept at the highest temperature of 1050±30°C for 2200±400min, then cooled in the furnace, the powder tablet was taken out and crushed to a particle size of 0.04-0.20 microns, and finally pure Y _3-x Yb _x SbO ₇ (0.5≤x ≤1) and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) powder photocatalytic materials.

2. The preparation process of the magnetic composite catalytic material with the structure of "magnetic particle core-photocatalyst shell" is as follows:

(1) γ-Fe _{2O 3} (ferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell) and γ-Fe ₂ O ₃ (ferromagnetic particle core)- Preparation of Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell):

Deposition by pulsed laser sputtering:

a. Target preparation: prepare Y _3-x Yb _x SbO ₇ (0.5≤x≤1) targets and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) targets by the above solid-phase sintering method, The target diameter is 10mm and the thickness is 2mm;

b. Select the substrate: use ferromagnetic particles γ-Fe ₂ O ₃ as the substrate;

c. Using a pulsed laser sputtering deposition instrument, the main wavelength of the laser is 248nm, the laser power density is 2-3J/cm ² , nitrogen is used as the protective atmosphere, and the pressure of nitrogen and oxygen (purity is 99.99%) is 8-10Pa. The initial pressure in the chamber is 6×10 ^-5 Pa to 2×10 ^-3 Pa, the distance from the target to the substrate is 3 to 7 cm, and the temperature of the substrate is 300 to 700°C, respectively sputtering Y _3-x Yb _x SbO ₇ (0.5≤x≤1) target and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) target to γ-Fe ₂ O ₃ substrate surface, on γ-Fe ₂ O ₃ substrate Deposit films with different thicknesses. The film deposition time is 90-120 minutes. The above two films are respectively treated in nitrogen or argon at 1340±10°C and 1340±10°C for 60±10min to crystallize and form Obtain the required magnetic composite catalytic materials γ-Fe ₂ O ₃ -Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and γ-Fe ₂ O ₃ -Y _3-x Ga _x SbO ₇ (0.5≤x ≤1).

Deposition method using multi-target magnetron sputtering:

a. Target preparation: prepare pure metal Yb, Ga, Sb, Y metal targets with a diameter of 5-6 cm;

b. Select the substrate: use ferromagnetic particles γ-Fe ₂ O ₃ as the substrate;

c. Using a multi-target magnetron sputtering apparatus, the sputtering power is 60-200W, with argon as the protective atmosphere, the pressure of argon and oxygen (purity is 99.99%) is 4-32mTorr, the flow ratio of oxygen (O ₂ /(O ₂ +Ar)) is 30% to 50%, the initial pressure in the deposition chamber is 3.3×10 ^-6 Torr to 1×10 ^-5 Torr, the distance from the target to the substrate is 4 to 15 cm, and the The temperature is 0-400° C., and the film deposition rate is 1-2 nm/min. Co-sputter pure metal Y, Yb and Sb targets onto the surface of the γ-Fe ₂ O ₃ substrate in a mixed gas of oxygen and argon, and form Y _3-x Yb _x SbO ₇ (0.5≤x≤ 1) Film layer, treat this film layer in nitrogen or argon at 1340±10°C for 60±10min; crystallize it to obtain the desired γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _{3- x} Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell); co-sputter pure metal Y, Ga and Sb targets onto the surface of γ-Fe ₂ O ₃ substrate in a mixed gas of oxygen and argon, in Deposit and form a Y _3-x Ga _x SbO ₇ (0.5≤x≤1) film layer on the substrate, treat this film layer in nitrogen or argon at 1340±10°C for 60±10min; crystallize it to obtain the Required γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell).

(2) SiO ₂ (paramagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell) and SiO ₂ (paramagnetic particle core)-Y _3-x Ga _x SbO ₇ Preparation of (0.5≤x≤1) (photocatalyst shell):

Deposition by pulsed laser sputtering:

a. Target preparation: prepare Y _3-x Yb _x SbO ₇ (0.5≤x≤1) targets and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) targets by the above solid-phase sintering method, The target diameter is 10mm and the thickness is 2mm;

b. Select the substrate: select paramagnetic particle SiO ₂ as the substrate;

c. Using a pulsed laser sputtering deposition instrument, the main wavelength of the laser is 248nm, the laser power density is 2-3J/cm ² , nitrogen is used as the protective atmosphere, and the pressure of nitrogen and oxygen (purity is 99.99%) is 8-10Pa. The initial pressure in the chamber is 6×10 ^{- -5} Pa to 2×10 ^-3 Pa, the distance from the target to the substrate is 3 to 7 cm, and the temperature of the substrate is 300 to 700°C, respectively sputtering Y _3-x Yb _x SbO ₇ (0.5≤x≤1) target and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) target to the SiO ₂ substrate surface, deposit films with different thicknesses on the SiO ₂ substrate, thin film The deposition time is 90 to 120 minutes, and the above two films are respectively treated in nitrogen or argon at 1340±10°C and 1340±10°C for 60±10min to crystallize them to obtain the desired magnetic composite catalyst. Materials SiO ₂ -Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and SiO ₂ -Y _3-x Ga _x SbO ₇ (0.5≤x≤1).

Deposition method using multi-target magnetron sputtering:

a. Target preparation: prepare pure metal Yb, Ga, Sb, Y metal targets with a diameter of 5-6 cm;

b. Select the substrate: select paramagnetic particle SiO ₂ as the substrate;

c. Using a multi-target magnetron sputtering apparatus, the sputtering power is 60-200W, with argon as the protective atmosphere, the pressure of argon and oxygen (purity is 99.99%) is 4-32mTorr, the flow ratio of oxygen (O ₂ /(O ₂ +Ar)) is 30% to 50%, the initial pressure in the deposition chamber is 3.3×10 ^-6 Torr to 1×10 ^-5 Torr, the distance from the target to the substrate is 4 to 15 cm, and the The temperature is 0-400° C., and the film deposition rate is 1-2 nm/min. Co-sputter pure metal Y, Yb and Sb targets onto the surface of SiO ₂ substrate in a mixed gas of oxygen and argon, and deposit Y _3-x Yb _x SbO ₇ (0.5≤x≤1) film on the substrate , treat this film in nitrogen or argon at 1340±10°C for 60±10min; crystallize it to obtain the desired SiO ₂ (paramagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤ x≤1) (photocatalyst shell); pure metal Y, Ga and Sb targets are co-sputtered to the surface of SiO ₂ substrate in a mixed gas of oxygen and argon, and Y _3-x Ga _x SbO is deposited on the substrate ₇ (0.5≤x≤1) film layer, treat this film layer in nitrogen or argon at 1340±10°C for 60±10min; crystallize it to obtain the desired SiO ₂ (paramagnetic particle core)-Y _3-x Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell).

(3) MnO (antiferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤x≤1) (photocatalyst shell) and MnO (antiferromagnetic particle core)-Y _3-x Ga _x SbO ₇ Preparation of (0.5≤x≤1) (photocatalyst shell):

Deposition by pulsed laser sputtering:

a. Target preparation: prepare Y _3-x Yb _x SbO ₇ (0.5≤x≤1) targets and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) targets by the above solid-phase sintering method, The target diameter is 10mm and the thickness is 2mm;

b. Select the substrate: select antiferromagnetic particle MnO as the substrate;

c. Using a pulsed laser sputtering deposition instrument, the main wavelength of the laser is 248nm, the laser power density is 2-3J/cm ² , nitrogen is used as the protective atmosphere, and the pressure of nitrogen and oxygen (purity is 99.99%) is 8-10Pa. The initial pressure in the chamber is 6×10 ^-5 Pa to 2×10 ^-3 Pa, the distance from the target to the substrate is 3 to 7 cm, and the temperature of the substrate is 300 to 700°C, respectively sputtering Y _3-x Yb _x SbO ₇ (0.5≤x≤1) target and Y _3-x Ga _x SbO ₇ (0.5≤x≤1) target are deposited on the surface of MnO substrate, and films with different thicknesses are deposited on the MnO particle substrate. The film deposition time For 90 to 120 minutes, the above two films were respectively treated in nitrogen or argon at 1340±10°C and 1340±10°C for 60±10min to crystallize them to obtain the required magnetic composite catalytic material MnO -Y _3-x Yb _x SbO ₇ (0.5≤x≤1) and MnO-Y _3-x Ga _x SbO ₇ (0.5≤x≤1).

Deposition method using multi-target magnetron sputtering:

a. Target preparation: prepare pure metal Yb, Ga, Sb, Y metal targets with a diameter of 5-6 cm;

b. Select the substrate: select antiferromagnetic particle MnO as the substrate;

c. Using a multi-target magnetron sputtering apparatus, the sputtering power is 60-200W, with argon as the protective atmosphere, the pressure of argon and oxygen (purity is 99.99%) is 4-32mTorr, the flow ratio of oxygen (O ₂ /(O ₂ +Ar)) is 30% to 50%, the initial pressure in the deposition chamber is 3.3×10 ^-6 Torr to 1×10 ^-5 Torr, the distance from the target to the substrate is 4 to 15 cm, and the The temperature is 0-400° C., and the film deposition rate is 1-2 nm/min. Co-sputter pure metal Y, Yb and Sb targets to the surface of MnO particle substrate in a mixed gas of oxygen and argon, and deposit Y _3-x Yb _x SbO ₇ (0.5≤x≤1) film layer on the substrate , treat this film in nitrogen or argon at 1340±10°C for 60±10min; crystallize it to obtain the desired MnO (antiferromagnetic particle core)-Y _3-x Yb _x SbO ₇ (0.5≤ x≤1) (photocatalyst shell); pure metal Y, Ga and Sb targets are co-sputtered to the surface of MnO substrate in a mixed gas of oxygen and argon, and Y _3-x Ga _x SbO ₇ is deposited on the substrate (0.5≤x≤1) film layer, treat this film layer in nitrogen or argon at 1340±10°C for 60±10min; crystallize it to obtain the required MnO (antiferromagnetic particle core)-Y _{3 -x} Ga _x SbO ₇ (0.5≤x≤1) (photocatalyst shell).

3. Establishment method of magnetic field-photocatalytic reaction system

The application of catalytic materials with a core-shell structure degrades wastewater through a reaction system composed of a magnetic field device and photocatalytic materials. The magnetic field device is an alternating magnetic field generator with adjustable strength. The magnetic field strength is selected from 0.3 to 1T (Tesla), and the light source is a xenon lamp. or high-pressure mercury lamp; using γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y ₂ YbSbO ₇ (photocatalytic shell), SiO ₂ (paramagnetic particle core)-Y ₂ YbSbO ₇ (photocatalytic shell) and MnO ( antiferromagnetic particle core)-Y ₂ YbSbO ₇ (photocatalyst shell) as a catalyst, or use γ-Fe ₂ O ₃ -Y ₂ GaSbO ₇ , SiO ₂ -Y ₂ GaSbO ₇ , MnO-Y ₂ GaSbO ₇ , the above three The volume percentages of the three kinds of magnetic composite photocatalytic materials each account for one-third. The above three kinds of magnetic composite catalyst particles are distributed in a gradient in the aqueous solution, and can be evenly distributed in the upper, middle and lower layers of the aqueous solution. Light sheet (λ > 420nm), and oxygen aeration is used at the same time. The entire light reaction was carried out in a closed and light-tight environment. The magnetic field strength can also be 0.05-1.5T (Tesla). The light source is a 300W xenon lamp and a 400W high pressure mercury lamp. Pentachlorophenol, dyes and Atrazine, typical refractory organic compounds in water, were selected as target degradation products.

The composite magnetic particles are controlled by the magnetic field to be distributed in a gradient in the aqueous solution containing organic matter, and the magnetic particle cores of different magnetic properties (ferromagnetic, paramagnetic and antiferromagnetic) are used to coat the new photocatalyst. These magnetic composite catalytic materials are under the action of a directional magnetic field It can promote the mixing of similar magnetic particles, avoid particle agglomeration, and make them completely and uniformly dispersed in the aqueous solution so that the magnetic composite catalytic material is evenly distributed in the upper, middle and lower layers of the aqueous solution. The static magnetic field and alternating magnetic field can also be flexibly applied according to the needs, and the distribution of strong magnetic and weak magnetic particles can be easily adjusted in a large range of length and composition, so that the photocatalyst coated on the surface of the magnetic particles can be combined with organic pollutants. And the light source is fully exposed, and the organic pollutants can be degraded efficiently under the irradiation of visible light (or ultraviolet light).

The application of core-shell structure catalytic materials also lies in using Y ₂ YbSbO ₇ or Y ₂ GaSbO ₇ powder as a catalyst, or supporting Pt, NiO and RuO ₂ as auxiliary catalysts respectively, the light source is a xenon lamp or a high-pressure mercury lamp, in a closed environment composed of multiple A glass pipeline controlled by a valve is used to decompose water to produce hydrogen in the reactor with internal lighting.

4. Characterization of Y ₂ YbSbO ₇ and Y ₂ GaSbO ₇

The results of XRD and XPS show that both Y ₂ YbSbO ₇ and Y ₂ GaSbO ₇ are single-phase, and the experimental raw materials are highly pure without any impurity phase.

Y₂YbSbO₇各衍射峰的(222)、(400)、(440)、(622)、(444)、(800)、(662)、(840)、(844)等晶面指数被标定。Y₂YbSbO₇中各个原子的空间原子位置参数被确定(见表1)。采用紫外可见漫反射光谱仪对Y₂YbSbO₇在光的照射下产生的特征吸收边进行测定，获得Y₂YbSbO₇的带隙宽度为2.521eV，获得Y₂YbSbO₇的能带结构，导带由Y的4d轨道、Yb的4f轨道和Sb的5p轨道构成，价带由O的2p轨道构成。The average atomic mole percentage of Y ₂ YbSbO ₇ measured by X-ray fluorescence spectrometer was Y:Yb:Sb:O=2.00:0.98:1.01:6.97. The XRD results of Y ₂ YbSbO ₇ were refined by Rietveld software, and the structure refinement factor RP value was R _P =10.09%. The space group of Y ₂ YbSbO ₇ is Fd-3m, the structure is cubic crystal system, pyrochlore structure, and the unit cell parameter a is 10.49977(8)

The (222), (400), (440), (622), (444), (800), (662), (840), (844) and other crystal plane indices of each diffraction peak of Y ₂ YbSbO ₇ were calibrated. The spatial atomic position parameters of each atom in Y ₂ YbSbO ₇ were determined (see Table 1). The characteristic absorption edge of Y ₂ YbSbO ₇ under the irradiation of light was measured by ultraviolet-visible diffuse reflectance spectrometer, and the band gap width of Y ₂ YbSbO ₇ was 2.521eV, and the energy band structure of Y ₂ YbSbO ₇ was obtained. The conduction band was The 4d orbital of Y, the 4f orbital of Yb, and the 5p orbital of Sb are composed, and the valence band is composed of the 2p orbital of O.

Y₂GaSbO₇各衍射峰的(222)、(400)、(440)、(622)、(444)、(800)、(662)、(840)、(844)等晶面指数被标定。Y₂GaSbO₇中各个原子的空间原子位置参数被确定(见表2)。采用紫外可见漫反射光谱仪对Y₂GaSbO₇在光的照射下产生的特征吸收边进行测定，获得Y₂GaSbO₇的带隙宽度为3.322eV，获得Y₂GaSbO₇的能带结构，导带由Y的4d轨道、Ga的4p轨道和Sb的5p轨道构成，价带由O的2p轨道构成。The average atomic mole percentage of Y ₂ GaSbO ₇ measured by X-ray fluorescence spectrometer is Y:Ga:Sb:O=2.00:0.97:1.02:6.99. The XRD results of Y ₂ GaSbO ₇ were refined by Rietveld software, and the structure refinement factor R _P value was R _P =12.36%. The space group of Y ₂ GaSbO ₇ is Fd-3m, the structure is cubic system, pyrochlore structure, and the unit cell parameter a is 10.17981(1)

The (222), (400), (440), (622), (444), (800), (662), (840), (844) and other crystal plane indices of each diffraction peak of Y ₂ GaSbO ₇ are calibrated. The spatial atomic position parameters of each atom in Y ₂ GaSbO ₇ were determined (see Table 2). The characteristic absorption edge of Y ₂ GaSbO ₇ under the irradiation of light was measured by ultraviolet-visible diffuse reflectance spectrometer, and the band gap width of Y ₂ GaSbO ₇ was 3.322eV, and the energy band structure of Y ₂ GaSbO ₇ was obtained. The conduction band was The 4d orbital of Y, the 4p orbital of Ga, and the 5p orbital of Sb are formed, and the valence band is formed of the 2p orbital of O.

Applications

1. Degradation of Atrazine in Wastewater Using Y ₂ GaSbO ₇ Powder

Put 0.8 g of Y ₂ GaSbO ₇ powder into 300 mL of atrazine aqueous solution to form a suspension system. The initial concentration of the atrazine aqueous solution is 0.1 mmol L ^-1 and the initial pH value is 7. Select a 300W xenon lamp to irradiate the atrazine solution with a cut-off filter (λ>420nm). During the experiment, the catalyst powder was maintained in a suspended state by means of a magnetic stirrer and oxygen aeration. The entire light reaction was carried out in a closed and light-tight environment. After 400 minutes, the removal rate of atrazine was 92.2%, the photon quantum efficiency was 0.31%, and the removal rate (mineralization rate) of total organic carbon (TOC) reached 88.3%.

2. Degradation of Atrazine in Wastewater Using Y ₂ YbSbO ₇ Powder

Put 0.8 g of Y ₂ YbSbO ₇ powder into 300 mL of atrazine aqueous solution to form a suspension system. The initial concentration of the atrazine aqueous solution is 0.1 mmol L ^-1 and the initial pH value is 7. Select a 300W xenon lamp to irradiate the atrazine solution with a cut-off filter (λ>420nm). During the experiment, the catalyst powder was maintained in a suspended state by means of a magnetic stirrer and oxygen aeration. The entire light reaction was carried out in a closed and light-tight environment. After 400 minutes, the removal rate of atrazine was 89.3%, the photon quantum efficiency was 0.29%, and the removal rate (mineralization rate) of total organic carbon (TOC) was 86.2%.

3. Using Y ₂ GaSbO ₇ powder to degrade pentachlorophenol in wastewater

Put 0.8g of Y ₂ GaSbO ₇ powder into 300mL pentachlorophenol aqueous solution to form a suspension system. The initial concentration of pentachlorophenol aqueous solution is 0.1mmol L ^-1 and the initial pH value is 7. Choose a 300W xenon lamp to irradiate the pentachlorophenol solution, and add a cut-off filter (λ>420nm). During the experiment, the catalyst powder was maintained in a suspended state by means of a magnetic stirrer and oxygen aeration. The entire light reaction was carried out in a closed and light-tight environment. After 400 minutes, the removal rate of pentachlorophenol was 93.4%, the light quantum efficiency was 0.33%, and the removal rate (mineralization rate) of total organic carbon (TOC) reached 89.1%.

4. Using Y ₂ YbSbO ₇ powder to degrade pentachlorophenol in wastewater

Put 0.8g of Y ₂ YbSbO ₇ powder into 300mL pentachlorophenol aqueous solution to form a suspension system. The initial concentration of pentachlorophenol aqueous solution is 0.1mmol L ^-1 and the initial pH value is 7. Choose a 300W xenon lamp to irradiate the pentachlorophenol solution, and add a cut-off filter (λ>420nm). During the experiment, the catalyst powder was maintained in a suspended state by means of a magnetic stirrer and oxygen aeration. The entire light reaction was carried out in a closed and light-tight environment. After 400 minutes, the removal rate of pentachlorophenol was 91.2%, the light quantum efficiency was 0.30%, and the removal rate (mineralization rate) of total organic carbon TOC reached 88.6%.

5. Using γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y ₂ GaSbO ₇ (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y ₂ GaSbO ₇ (photocatalyst shell) and MnO (antiferromagnetic Particle core)-Y ₂ GaSbO ₇ (photocatalyst shell) degrades atrazine in wastewater using a self-made magnetic field-photocatalytic reaction system, through an alternating magnetic field generator with adjustable magnetic field strength, and the magnetic field strength is selected from 0.3 to 0.6T ( Tesla). The light source is a 300W xenon lamp. Using γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y ₂ GaSbO ₇ (photocatalytic shell), SiO ₂ (paramagnetic particle core)-Y ₂ GaSbO ₇ (photocatalytic shell) and MnO (antiferromagnetic particle core) )-Y ₂ GaSbO ₇ (photocatalyst shell) was used as the catalyst, and the volume percentage of the above three magnetic composite photocatalytic materials each accounted for one-third, and atrazine, which is typically difficult to degrade in water, was selected as the target degradation product. When the magnetic field strength is 0.3-0.6 tesla, the above three kinds of magnetic composite catalyst particles are distributed in a gradient in the aqueous solution containing atrazine, and can be uniformly distributed in the upper, middle and lower layers of the aqueous solution. At this time, 900 mL of atrazine aqueous solution was selected, and the weight of Y ₂ GaSbO ₇ coated on the surface of all magnetic particles was close to 2.4 g. The initial concentration of atrazine aqueous solution was 0.1 mmol L ^-1 , and the initial pH value was 7. Select a 300W xenon lamp to irradiate the atrazine solution with a cut-off filter (λ>420nm). During the experiment, oxygenation and aeration were also used. The entire light reaction was carried out in a closed and light-tight environment. Finally, the flexible application of static magnetic field and alternating magnetic field can make the photocatalyst coated on the surface of magnetic particles fully contact with organic pollutants and light sources. After 400 minutes of visible light irradiation, the removal rate of atrazine reaches 96.8%, and the photon quantum efficiency The removal rate (mineralization rate) of total organic carbon TOC is 93.2%.

6. Using γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y ₂ YbSbO ₇ (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y ₂ YbSbO ₇ (photocatalyst shell) and MnO (antiferromagnetic Particle core)-Y ₂ YbSbO ₇ (photocatalyst shell) for degradation of atrazine in wastewater

A self-made magnetic field-photocatalytic reaction system is used, and an alternating magnetic field generator with adjustable magnetic field strength is used, and the magnetic field strength is selected from 0.3 to 0.6T (Tesla). The light source is a 300W xenon lamp. Using γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y ₂ YbSbO ₇ (photocatalytic shell), SiO ₂ (paramagnetic particle core)-Y ₂ YbSbO ₇ (photocatalytic shell) and MnO (antiferromagnetic particle core) )-Y ₂ YbSbO ₇ (photocatalyst shell) was used as the catalyst, and the volume percentage of the above three magnetic composite photocatalytic materials each accounted for one-third, and atrazine, which is typically difficult to degrade in water, was selected as the target degradation product. When the magnetic field strength is 0.3-0.6 tesla, the above three kinds of magnetic composite catalyst particles are distributed in a gradient in the aqueous solution containing atrazine, and can be uniformly distributed in the upper, middle and lower layers of the aqueous solution. At this time, 900 mL of atrazine aqueous solution was selected, and the weight of Y ₂ YbSbO ₇ coated on the surface of all magnetic particles was close to 2.4 g. The initial concentration of atrazine aqueous solution was 0.1 mmol L ^-1 , and the initial pH value was 7. Select a 300W xenon lamp to irradiate the atrazine solution with a cut-off filter (λ>420nm). During the experiment, oxygenation and aeration were also used. The entire light reaction was carried out in a closed and light-tight environment. Finally, the flexible application of static magnetic field and alternating magnetic field can make the photocatalyst coated on the surface of magnetic particles fully contact with organic pollutants and light sources. After 400 minutes of visible light irradiation, the removal rate of atrazine reaches 93.5%, and the photon quantum efficiency is 0.31%, and the removal rate (mineralization rate) of total organic carbon TOC reaches 90.4%.

7. Using γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y ₂ GaSbO ₇ (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y ₂ GaSbO ₇ (photocatalyst shell) and MnO (antiferromagnetic Particle core)-Y ₂ GaSbO ₇ (photocatalyst shell) for degradation of pentachlorophenol in wastewater

A self-made magnetic field-photocatalytic reaction system is used, and an alternating magnetic field generator with adjustable magnetic field strength is used, and the magnetic field strength is selected from 0.3 to 0.6T (Tesla). The light source is a 300W xenon lamp. Using γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y ₂ GaSbO ₇ (photocatalytic shell), SiO ₂ (paramagnetic particle core)-Y ₂ GaSbO ₇ (photocatalytic shell) and MnO (antiferromagnetic particle core) )-Y ₂ GaSbO ₇ (photocatalyst shell) was used as the catalyst, and the above three magnetic composite photocatalytic materials each accounted for one-third of the volume percentage, and the typical refractory pentachlorophenol in water was selected as the target degradation product. When the magnetic field strength is 0.3-0.6 tesla, the above three kinds of magnetic composite catalyst particles are distributed in a gradient in the aqueous solution containing pentachlorophenol, and can be uniformly distributed in the upper, middle and lower layers of the aqueous solution. At this time, 900mL pentachlorophenol aqueous solution is selected, and the weight of Y ₂ GaSbO ₇ coated on the surface of all magnetic particles is close to 2.4g. The initial concentration of pentachlorophenol aqueous solution is 0.1mmol L ^-1 , and the initial pH value is 7. Choose a 300W xenon lamp to irradiate the pentachlorophenol solution, and add a cut-off filter (λ>420nm). During the experiment, oxygenation and aeration were also used. The entire light reaction was carried out in a closed and light-tight environment. Finally, the static magnetic field and alternating magnetic field can be applied flexibly, so that the photocatalyst coated on the surface of the magnetic particles can fully contact with organic pollutants and light sources. After 400 minutes of visible light irradiation, the removal rate of pentachlorophenol reaches 96.7%, and the photon quantum efficiency is 0.35%, the removal rate (mineralization rate) of total organic carbon TOC reaches 93.4%.

8. Using γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y ₂ YbSbO ₇ (photocatalyst shell), SiO ₂ (paramagnetic particle core)-Y ₂ YbSbO ₇ (photocatalyst shell) and MnO (antiferromagnetic Particle core)-Y ₂ YbSbO ₇ (photocatalyst shell) for degradation of pentachlorophenol in wastewater

A self-made magnetic field-photocatalytic reaction system is used, and an alternating magnetic field generator with adjustable magnetic field strength is used, and the magnetic field strength is selected from 0.3 to 0.6T (Tesla). The light source is a 300W xenon lamp. Using γ-Fe ₂ O ₃ (ferromagnetic particle core)-Y ₂ YbSbO ₇ (photocatalytic shell), SiO ₂ (paramagnetic particle core)-Y ₂ YbSbO ₇ (photocatalytic shell) and MnO (antiferromagnetic particle core) )-Y ₂ YbSbO ₇ (photocatalyst shell) was used as the catalyst, and the volume percentage of the above three magnetic composite photocatalytic materials each accounted for one-third, and the typical refractory pentachlorophenol in water was selected as the target degradation product. When the magnetic field strength is 0.3-0.6 tesla, the above three kinds of magnetic composite catalyst particles are distributed in a gradient in the aqueous solution containing pentachlorophenol, and can be uniformly distributed in the upper, middle and lower layers of the aqueous solution. At this time, 900 mL of pentachlorophenol aqueous solution was selected, and the weight of Y ₂ YbSbO ₇ coated on the surface of all magnetic particles was close to 2.4 g. The initial concentration of pentachlorophenol aqueous solution was 0.1 mmol L ^-1 , and the initial pH value was 7. Choose a 300W xenon lamp to irradiate the pentachlorophenol solution, and add a cut-off filter (λ>420nm). During the experiment, oxygenation and aeration were also used. The entire light reaction was carried out in a closed and light-tight environment. Finally, the flexible application of static and alternating magnetic fields can make the photocatalyst coated on the surface of the magnetic particles fully contact with organic pollutants and light sources. After 400 minutes of visible light irradiation, the removal rate of pentachlorophenol reaches 94.3%, and the photon quantum efficiency is 0.32%, the removal rate (mineralization rate) of total organic carbon TOC reaches 91.5%.

9. Using Y ₂ GaSbO ₇ to decompose water to produce hydrogen

The experiment of producing hydrogen by splitting water was carried out in a closed glass tube internal lighting reactor controlled by multiple valves. The light source used was a 300W xenon lamp (incident luminous flux: 4.513×10 ^-6 Einstein L ^-1 s ^-1 , cut-off at 420nm filter) or a 400W (incident luminous flux: 6.013×10 ^-6 Einstein L ^-1 s ^-1 , 390nm cut-off filter) high-pressure mercury lamp, put 0.8g of Y ₂ GaSbO ₇ powder in 300mL pure water. The overflow hydrogen yield was determined using a gas chromatograph-mass spectrometer with a TCD connected to a closed-loop internally illuminated reactor. Before the reaction, various gases in the closed-loop internal lighting reactor were removed, and argon was charged into the reactor until the oxygen and nitrogen in the reactor were completely removed. After 24 hours under the irradiation of a xenon lamp, the production of hydrogen was 762.4 micromoles, and the production of oxygen was 378.5 micromoles; after 24 hours under the irradiation of a high-pressure mercury lamp, the production of hydrogen was 2148.8 micromoles, and the production of oxygen was 1069.2 micromoles.

Use Y ₂ GaSbO ₇ powder as catalyst, load Pt respectively, NiO and RuO ₂ assist catalyst to decompose water to produce hydrogen, the main wavelength of incident light is λ=360nm, catalyst 0.8g, pure water 300mL, 50mL CH ₃ OH, light source 400W High-pressure mercury lamp, with 0.2wt%-Pt/Y ₂ GaSbO ₇ as the composite catalyst, the hydrogen production after 24 hours is 5.46mmol; with 1.0wt%-NiO/Y ₂ GaSbO ₇ as the composite catalyst, the hydrogen production after 24 hours 4.12mmol; with 1.0wt%-RuO ₂ /Y ₂ GaSbO ₇ as the composite catalyst, the hydrogen production after 24 hours was 3.18mmol.

10. Using Y ₂ YbSbO ₇ to decompose water to produce hydrogen

The experiment of producing hydrogen by splitting water was carried out in a closed glass tube internal lighting reactor controlled by multiple valves. The light source used was a 300W xenon lamp (incident luminous flux: 4.513×10 ^-6 Einstein L ^-1 s ^-1 , cut-off at 420nm filter) or a 400W (incident luminous flux: 6.013×10 ^-6 Einstein L ^-1 s ^-1 , 390nm cut-off filter) high-pressure mercury lamp, put 0.8g of Y ₂ YbSbO ₇ powder in 300mL pure water. The overflow hydrogen yield was determined using a gas chromatograph-mass spectrometer with a TCD connected to a closed-loop internally illuminated reactor. Before the reaction, various gases in the closed-loop internal lighting reactor were removed, and argon was charged into the reactor until the oxygen and nitrogen in the reactor were completely removed. After 24 hours under the irradiation of a xenon lamp, the production of hydrogen was 658.6 micromoles, and the production of oxygen was 326.1 micromoles; after 24 hours under the irradiation of a high-pressure mercury lamp, the production of hydrogen was 1836.5 micromoles, and the production of oxygen was 915.8 micromoles.

Use Y ₂ YbSbO ₇ powder as a catalyst, load Pt, NiO and RuO ₂ to assist the catalyst to decompose water to produce hydrogen, the main wavelength of the incident light is λ=360nm, the catalyst is 0.8g, pure water is 300mL, CH ₃ OH is 50mL, and the light source is 400W High-pressure mercury lamp, with 0.2wt _% -Pt/ _{Y2YbSbO 7} as the composite catalyst, the hydrogen production after 24 hours is 4.72mmol; with 1.0wt%-NiO/ _Y2YbSbO7 as the composite catalyst, the hydrogen production after 24 hours 3.89mmol; with 1.0wt%-RuO ₂ /Y ₂ YbSbO ₇ as the composite catalyst, the hydrogen production after 24 hours was 2.63mmol.

Claims (2)

1. the catalysis material of nucleocapsid structure is characterized in that using following structural formula: γ-Fe ₂O ₃-Y _3-xYb _xSbO ₇0.5≤x≤1, γ-Fe ₂O ₃-Y _3-xGa _xSbO ₇0.5≤x≤1, SiO ₂-Y _3-xYb _xSbO ₇0.5≤x≤1, SiO ₂-Y _3-xGa _xSbO ₇0.5≤x≤1, MnO-Y _3-xYb _xSbO ₇0.5≤x≤1 or MnO-Y _3-xGa _xSbO ₇0.5≤x≤1, γ-Fe ₂O ₃, SiO ₂With the particle diameter of MnO be the 0.06-2 micron, Y _3-xYb _xSbO ₇, Y _3-xGa _xSbO ₇Particle diameter is the 0.07-2.1 micron behind the parcel.

2. the application of the catalysis material of nucleocapsid structure, it is characterized in that the reaction system degrading waste water by magnetic field device and catalysis material formation, magnetic field device is the adjustable alternating magnetic field generator of intensity, and magnetic field intensity is chosen 0.3～0.6T, and light source is xenon lamp or high-pressure sodium lamp; Adopt γ-Fe ₂O ₃-Y ₂YbSbO ₇, SiO ₂-Y ₂YbSbO ₇And MnO-Y ₂YbSbO ₇As catalyst, or adopt γ-Fe ₂O ₃-Y ₂GaSbO ₇, SiO ₂-Y ₂GaSbO ₇, MnO-Y ₂GaSbO ₇The percent by volume of above-mentioned three kinds of magnetic coupling catalysis materials respectively accounts for 1/3rd, above-mentioned three kinds of magnetic coupling catalyst granules distribution gradient in the aqueous solution, and make it be evenly distributed on upper, middle and lower-ranking in the aqueous solution, adopt edge filter, λ〉420nm, and adopt simultaneously oxygenic aeration; Whole illumination reaction carries out under airtight lighttight environment.

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