CN104001491B - A kind of CeO2/TiO2 nanocomposite hollow sphere catalyst and preparation method thereof - Google Patents

Abstract

The invention discloses a CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst and a preparation method thereof. The CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst first uses polystyrene as a template, and tetrabutyl titanate and hexahydrate CeO ₂ /TiO ₂ coated polystyrene composite microspheres were prepared by combining sol-gel method and precipitation method, and then calcined to obtain CeO ₂ /TiO ₂ nanocomposite hollow sphere catalysts; the polystyrene The amount of ethylene, tetrabutyl titanate and cerium nitrate hexahydrate, according to polystyrene: tetrabutyl titanate: cerium nitrate hexahydrate is 0.1‑0.3g: 0.2‑8×10 ^‑3 mol: 1‑6×10 ^-3 mol. The CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst prepared by the invention has uniform size and good photocatalysis and thermal stability.

Description

A kind of CeO2/TiO2 nanocomposite hollow sphere catalyst and preparation method thereof

technical field

The invention relates to an inorganic composite hollow sphere catalyst and a preparation method thereof, in particular to a CeO ₂ /TiO ₂ nanometer composite hollow sphere catalyst with controllable particle size and a preparation method thereof.

Background technique

TiO ₂ is a photocatalyst and environmental catalyst with good thermal stability, strong oxidation ability, low cost and easy availability. _TiO2 microspheres with a hollow structure are widely used in the field of photocatalysis due to their structural characteristics of low density, large specific surface area, good surface permeability, high light harvesting rate and the characteristics of _TiO2 itself. However, TiO ₂ can only absorb ultraviolet light with a wavelength of less than 387nm, which has a low utilization rate of solar energy. Moreover, the recombination rate of photogenerated carriers in TiO ₂ is high, and the quantum efficiency is low, which limits the practical application of TiO ₂ hollow microspheres. Combining other semiconductors with TiO ₂ can take advantage of the interface coupling effect between the two to broaden the photoresponse range, and can inhibit the recombination of photogenerated carriers and improve photocatalytic activity. There have been patent reports on the preparation of _TiO2 composite hollow spheres. For example, the patent with the publication number CN101905153A uses carbon spheres as a template to prepare a composite hollow sphere of zinc oxide and titanium oxide and applies it to photodegradable cationic blue dyes; the patent with the publication number CN101623644A uses hydrothermal method and two-step dipping method Composite hollow spheres of cadmium sulfide and titanium oxide were prepared by sol-gel method and applied to photodegradation of water for hydrogen production.

As an important rare earth oxide, ceria has been widely used in the fields of fuel cells, waste water and gas treatment, and photocatalysis due to its high oxygen storage and release, oxygen ion conductivity, and strong redox ability. However, the excellent oxygen storage performance of ceria is related to its thermal resistance, low-temperature reactivity, and structural stability, and these influencing factors make ceria unable to meet the requirements of high-temperature applications. Combining CeO ₂ and TiO ₂ can improve the thermal stability, structure and electronic properties of CeO ₂ through the interaction between titanium and cerium atoms and the regulation of structure. At present, the literature has reported the preparation of CeO ₂ and TiO ₂ nanoparticles by sol-gel method, homogeneous co-precipitation method and solvothermal method. (Chiara G, et al.Structural and spectroscopic characterization of CeO ₂ -TiO ₂ mixed oxides[J].Journal of Materials Chemistry A,2013,1,10918-10926; Benjaram MR and Ataullah K. Structural Characterization of CeO ₂ -TiO ₂ and V ₂ O ₅ /CeO ₂ -TiO ₂ Catalysts by Raman and XPS Techniques[J]. The Journal of Chemical Physics B,2003,107,5162-5167; Chockalingam K and Paramasivan G. Solvothermal Synthesis of CeO ₂ -TiO ₂ Nanocomposite for VisibleLight Photocatalytic Detoxification of Cyanide [J]. Sustainable Chemistry & Engineering, 2013, 1, 1555-1563).

Contents of the invention

One of the objectives of the present invention is to provide a CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst, which has the characteristics of hollow spherical structure and ordinary CeO ₂ /TiO ₂ composite oxide particles, and has high thermal stability, high specific surface area, excellent Light harvesting efficiency and oxygen storage and release capacity.

The second object of the present invention is to provide a method for preparing the aforementioned CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst.

Technical principle of the present invention

Hollow nanoparticles, as a special kind of nanostructure, are an increasingly important research area at the frontiers of chemistry and materials science in recent years, which are clearly characterized by large internal pores. Hollow micro-nanostructures have many unique properties such as large specific surface area, high stability, low density, high refractive index, good surface chemical properties and permeability, and are widely used in microchemical reactors, sensors and catalytic materials. .

CeO ₂ /TiO ₂ nanocomposite hollow spheres prepared with polystyrene spheres as templates have uniform size, good dispersion and controllable morphology. CeO ₂ /TiO ₂ nanocomposite hollow spheres not only have high thermal stability, but also have a higher specific surface area, which is beneficial to improve the storage performance of cerium oxide.

Technical scheme of the present invention

A CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst, that is, firstly using polystyrene as a template, using tetrabutyl titanate and cerium nitrate hexahydrate as raw materials, and preparing CeO ₂ /TiO 2 by combining sol-gel method and precipitation method TiO ₂ coated polystyrene composite microspheres, and then calcined to obtain CeO ₂ /TiO ₂ nanocomposite hollow sphere catalysts;

Among them, the amount of polystyrene, tetrabutyl titanate and cerium nitrate hexahydrate is 0.1-0.3g:0.2-8×10 ^-3 mol:1- 6×10 ^-3 mol.

The above _- mentioned CeO2/ _TiO2 nanocomposite hollow sphere catalyst preparation method specifically includes the following steps:

(1) After mixing 0.1-0.3g polystyrene, 0.5-2g deionized water, 10-50μL concentrated ammonia water and 20mL absolute ethanol, control the temperature at 60-75℃ and the speed of 300-500r/min for reaction After 2-4h, the reaction solution 1 was obtained;

The particle size of the polystyrene balls is about 200-500nm;

(2) Dissolve 0.2-8×10 ^-3 mol tetrabutyl titanate in 20 mL of absolute ethanol to prepare a 0.01-0.40 mol/L tetra-n-butyl titanate ethanol solution;

Add the ethanol solution of tetra-n-butyl titanate with a concentration of 0.01-0.40mol/L into the reaction solution 1 obtained in step (1) within 0.5-1h, control the temperature at 60-75°C and the rotation speed at 300-500r/min for reaction 2-4h, to obtain the reaction solution 2;

(3) Dissolve 1-6×10 ^-3 mol of cerium nitrate hexahydrate in 20 mL of absolute ethanol to prepare a 0.05-0.3 mol/L cerium nitrate ethanol solution;

Add the ethanol solution of cerium nitrate with a concentration of 0.05-0.3mol/L into the reaction solution 2 obtained in step (2) within 0.5-1h, control the temperature at 60-75°C, and carry out the reaction at 300-500r/min for 2-4h, Obtain reaction solution 3;

The obtained reaction solution 3 was centrifuged, and the obtained precipitate was dried at 60-80° C. for 8-10 h to obtain a light yellow powder;

The light yellow powder is calcined at 500-800°C for 3-5h, and naturally cooled to room temperature to obtain the CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst.

The CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst obtained above has a uniform particle size, good dispersion, and a particle size of 216nm-580nm, and has good photocatalytic degradation ability, especially photocatalytic degradation of Rhodamine B.

Beneficial effects of the present invention

A CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst of the present invention has both the characteristics of a hollow spherical structure and ordinary CeO ₂ /TiO ₂ composite oxide particles, so it has high thermal stability, high specific surface area, and excellent light harvesting efficiency and oxygen storage and release capabilities, and has potential application prospects in the fields of catalysis, fuel cells and adsorption materials.

Further, the preparation method of a CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst of the present invention, because its preparation process adopts polystyrene as template, dissolves titanium salt and cerium salt with organic solvent, utilizes electrostatic adsorption to make nano-titanium oxide and cerium oxide deposition, calcining to remove the template to obtain CeO2/ _TiO2 nanocomposite hollow spheres, so the preparation method of the present invention has simple preparation process, mild reaction conditions, and can effectively control the microscopic shape of _CeO2 / _{TiO2 nanocomposite} hollow spheres appearance and other characteristics, and the finally obtained CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst has uniform size and good dispersibility.

Description of drawings

Fig. 1, the CeO of embodiment 5 gained CeO ₂ / _TiO TEM figure of nanocomposite hollow sphere catalyst;

Fig. 2, the CeO of embodiment 5 gained CeO ₂ / _TiO The SEM figure of nanocomposite hollow sphere catalyst;

Fig. 3 , photodegradation of rhodamine B by the CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst obtained in Example 5.

detailed description

The present invention will be further described in detail below by means of embodiments and in conjunction with the accompanying drawings, but the present invention is not limited.

The reagents used in the various examples of the present invention are commercially available unless otherwise specified.

Polystyrene balls, the concentration is 2.5% w/v, Aladdin Reagent Co., Ltd.; tetrabutyl titanate, cerium nitrate hexahydrate, absolute ethanol, concentrated ammonia water are of analytical grade, from Sinopharm Chemical Reagent Co., Ltd.;

The CeO ₂ -TiO ₂ composite oxides in the prior art are carried out according to the literature (Chiara G, et al. Structural and spectroscopic characterization of CeO ₂ –TiO ₂ mixed oxides[J]. Journal of Materials Chemistry A, 2013, 1, 10918-10926) preparation.

Example 1

A CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst, that is, firstly using polystyrene as a template, using tetrabutyl titanate and cerium nitrate hexahydrate as wall materials, and preparing CeO by combining sol-gel method and precipitation method ₂ /TiO ₂ coated polystyrene composite microspheres, and then calcined to obtain CeO ₂ /TiO ₂ nanocomposite hollow microsphere catalysts;

Among them, the amount of polystyrene, tetrabutyl titanate and cerium nitrate hexahydrate is 0.1g: 0.2×10 ^-3 mol: 1×10 ^-3 mol for polystyrene: tetrabutyl titanate: cerium nitrate hexahydrate .

The above _- mentioned CeO2/ _TiO2 nanocomposite hollow sphere catalyst preparation method specifically includes the following steps:

(1) Mix 0.1g polystyrene, 0.5g deionized water, 50μL concentrated ammonia water and 20mL absolute ethanol evenly, then control the temperature at 60°C and the rotation speed at 300r/min for 2 hours to obtain the reaction solution 1;

The particle size of the polystyrene sphere is about 200nm;

(2) Dissolve 0.2×10 ^-3 mol tetrabutyl titanate in 20 mL of absolute ethanol to prepare a 0.01 mol/L tetra-n-butyl titanate ethanol solution;

Add the tetra-n-butyl titanate ethanol solution with a concentration of 0.01mol/L to the reaction solution 1 obtained in step (1) within 0.5h, and react for 2h at a temperature of 60°C and a rotation speed of 300r/min to obtain a reaction solution 2 ;

(3) Dissolve 1×10 ^-3 mol of cerium nitrate hexahydrate in 20 mL of absolute ethanol to prepare a 0.05 mol/L cerium nitrate ethanol solution;

Add the ethanol solution of cerium nitrate with a concentration of 0.05mol/L to the reaction solution 2 obtained in step (2) within 0.5h, and carry out the reaction for 2h at a controlled temperature of 60°C and a rotation speed of 300r/min to obtain the reaction solution 3;

The obtained reaction solution 3 was centrifuged, and the obtained precipitate was dried at 60° C. for 8 hours to obtain a light yellow powder;

The light yellow powder was calcined at 500° C. for 3 hours, and cooled naturally to room temperature to obtain a CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst with a particle size of 216 nm.

Example 2

A CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst, that is, firstly using polystyrene as a template, using tetrabutyl titanate and cerium nitrate hexahydrate as wall materials, and preparing CeO by combining sol-gel method and precipitation method ₂ /TiO ₂ coated polystyrene composite microspheres, and then calcined to obtain CeO ₂ /TiO ₂ nanocomposite hollow sphere catalysts;

Among them, the amount of polystyrene, tetrabutyl titanate and cerium nitrate hexahydrate is 0.3g: 8×10 ^-3 mol: 4×10 ^-3 mol for polystyrene: tetrabutyl titanate: cerium nitrate hexahydrate .

The above _- mentioned CeO2/ _TiO2 nanocomposite hollow sphere catalyst preparation method specifically includes the following steps:

(1) Mix 0.3g polystyrene, 2g deionized water, 10μL concentrated ammonia water and 20mL absolute ethanol evenly, control the temperature at 70°C, and react at a speed of 400r/min for 4 hours to obtain the reaction solution 1;

The particle size of the polystyrene sphere is about 400nm;

(2) Dissolve 8×10 ^-3 mol tetrabutyl titanate in 20 mL of absolute ethanol to prepare a 0.40 mol/L tetra-n-butyl titanate ethanol solution;

Add the tetra-n-butyl titanate ethanol solution with a concentration of 0.40 mol/L to the reaction solution 1 obtained in step (1) within 1 hour, and carry out the reaction for 4 hours at a controlled temperature of 70°C and a rotation speed of 400 r/min to obtain a reaction solution 2;

(3) Dissolve 4×10 ^-3 mol of cerium nitrate hexahydrate in 20 mL of absolute ethanol to prepare a 0.2 mol/L cerium nitrate ethanol solution;

Add the ethanol solution of cerium nitrate with a concentration of 0.2mol/L to the reaction solution 2 obtained in step (2) within 1 hour, and carry out the reaction for 4 hours at a controlled temperature of 70°C and a rotation speed of 400r/min to obtain the reaction solution 3;

The obtained reaction solution 3 was centrifuged, and the obtained precipitate was dried at 80° C. for 9 hours to obtain a light yellow powder;

The pale yellow powder was calcined at 500° C. for 5 hours, and cooled naturally to room temperature to obtain a CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst with a particle size of 440 nm.

Example 3

A CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst, that is, firstly using polystyrene as a template, using tetrabutyl titanate and cerium nitrate hexahydrate as wall materials, and preparing CeO by combining sol-gel method and precipitation method ₂ /TiO ₂ coated polystyrene composite microspheres, and then calcined to obtain CeO ₂ /TiO ₂ nanocomposite hollow sphere catalysts;

Among them, the amount of polystyrene, tetrabutyl titanate and cerium nitrate hexahydrate, according to polystyrene: tetrabutyl titanate: cerium nitrate hexahydrate is 0.2g: 4×10 ^-3 mol: 6×10 ^-3 mol .

The above _- mentioned CeO2/ _TiO2 nanocomposite hollow sphere catalyst preparation method specifically includes the following steps:

(1) Mix 0.2g polystyrene, 1g deionized water, 30μL concentrated ammonia water and 20mL absolute ethanol evenly, control the temperature at 75°C, and react at a speed of 500r/min for 3 hours to obtain the reaction solution 1;

The particle diameter of the polystyrene sphere is about 500nm;

(2) Dissolve 4×10 ^-3 mol tetrabutyl titanate in 20 mL of absolute ethanol to prepare a 0.2 mol/L tetra-n-butyl titanate ethanol solution;

Add the tetra-n-butyl titanate ethanol solution with a concentration of 0.2 mol/L into the solution 1 obtained in step (1) within 0.8 hours, and react for 3 hours at a controlled temperature of 75°C and a rotation speed of 500r/min to obtain a reaction solution 2;

(3) Dissolve 6×10 ^-3 mol of cerium nitrate hexahydrate in 20 mL of absolute ethanol to prepare a 0.3 mol/L cerium nitrate ethanol solution;

Add the ethanol solution of cerium nitrate with a concentration of 0.3mol/L to the solution 2 obtained in step (2) within 0.8h, and react for 3h at a temperature of 75°C and a rotation speed of 500r/min to obtain a reaction solution 3;

Then the obtained reaction solution 3 was centrifuged, and the obtained precipitate was dried at 70° C. for 10 h to obtain a light yellow powder;

Then the light yellow powder was calcined at 800° C. for 4 hours, and naturally cooled to room temperature to obtain a CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst with a particle size of 580 nm.

Example 4

A CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst, that is, firstly using polystyrene as a template, using tetrabutyl titanate and cerium nitrate hexahydrate as wall materials, and preparing CeO by combining sol-gel method and precipitation method ₂ /TiO ₂ coated polystyrene composite microspheres, and then calcined to obtain CeO ₂ /TiO ₂ nanocomposite hollow sphere catalysts;

Among them, the amount of polystyrene, tetrabutyl titanate and cerium nitrate hexahydrate, according to polystyrene: tetrabutyl titanate: cerium nitrate hexahydrate is 0.3g: 2×10 ^-3 mol: 3×10 ^-3 mol .

The above _- mentioned CeO2/ _TiO2 nanocomposite hollow sphere catalyst preparation method specifically includes the following steps:

(1) Mix 0.3g polystyrene, 0.5g deionized water, 40μL concentrated ammonia water and 20mL absolute ethanol evenly, control the temperature at 65°C, and react at a speed of 400r/min for 2 hours to obtain the reaction solution 1;

The particle diameter of the polystyrene sphere is about 300nm;

(2) Dissolve 2×10 ^-3 mol tetrabutyl titanate in 20 mL of absolute ethanol to prepare a 0.10 mol/L tetra-n-butyl titanate ethanol solution;

Add the tetra-n-butyl titanate ethanol solution with a concentration of 0.10 mol/L into the solution 1 obtained in step (1) within 1 hour, and react for 3 hours at a temperature of 65°C and a rotation speed of 400 r/min to obtain a reaction solution 2;

(3) Dissolve 3×10 ^-3 mol of cerium nitrate hexahydrate in 20 mL of absolute ethanol to prepare a 0.15 mol/L cerium nitrate ethanol solution;

Add the ethanol solution of cerium nitrate with a concentration of 0.15mol/L to the reaction solution 2 obtained in step (2) within 1 hour, and carry out the reaction at a temperature of 65°C and a rotation speed of 400r/min for 2-4 hours to obtain the reaction solution 3;

The obtained reaction solution 3 was centrifuged, and the obtained precipitate was dried at 70° C. for 8 h to obtain a light yellow powder;

The light yellow powder was calcined at 600° C. for 4 hours, and naturally cooled to room temperature to obtain a CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst with a particle size of 326 nm.

Example 5

A CeO ₂ -TiO ₂ nanocomposite hollow sphere catalyst, that is, firstly using polystyrene as a template, using tetrabutyl titanate and cerium nitrate hexahydrate as wall materials, and preparing CeO by combining sol-gel method and precipitation method ₂ /TiO ₂ coated polystyrene composite microspheres, and then calcined to obtain CeO ₂ /TiO ₂ nanocomposite hollow sphere catalysts;

Among them, the amount of polystyrene, tetrabutyl titanate and cerium nitrate hexahydrate is 0.2g: 1×10 ^-3 mol: 1×10 ^-3 mol for polystyrene: tetrabutyl titanate: cerium nitrate hexahydrate .

The above _- mentioned CeO2/ _TiO2 nanocomposite hollow sphere catalyst preparation method specifically includes the following steps:

(1) Mix 0.2g polystyrene, 1g deionized water, 40μL concentrated ammonia water and 20mL absolute ethanol evenly, control the temperature at 60°C, and react at a speed of 300r/min for 2 hours to obtain reaction solution 1;

The particle size of the polystyrene sphere is about 200nm;

(2) Dissolve 1×10 ^-3 mol tetrabutyl titanate in 20 mL of absolute ethanol to prepare a 0.05 mol/L tetra-n-butyl titanate ethanol solution;

Add the tetra-n-butyl titanate ethanol solution with a concentration of 0.05 mol/L into the reaction solution 1 obtained in step (1) within 1 hour, and carry out the reaction for 4 hours at a controlled temperature of 60°C and a rotation speed of 300 r/min to obtain a reaction solution 2;

(3) Dissolve 1×10 ^-3 mol of cerium nitrate hexahydrate in 20 mL of absolute ethanol to prepare a 0.05 mol/L cerium nitrate ethanol solution;

Add the ethanol solution of cerium nitrate with a concentration of 0.05mol/L to the solution 2 obtained in step (2) within 1 hour, and carry out the reaction for 2 hours at a controlled temperature of 60°C and a rotational speed of 300r/min to obtain the reaction solution 3;

The obtained reaction solution 3 was centrifuged, and the obtained precipitate was dried at 60° C. for 9 hours to obtain a light yellow powder;

The pale yellow powder was calcined at 500° C. for 3 hours, and cooled naturally to room temperature to obtain a CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst with a particle size of 220 nm.

The CeO ₂ / _{TiO 2} nanocomposite hollow spheres obtained above were tested with a transmission electron microscope (Hitachi H-600, Hitachi High-Tech Co., Ltd.). /TiO ₂ nanocomposite hollow spheres with a particle size of 220nm.

Adopt scanning electron microscope instrument (Hitachi S-3400N, Hitachi high-tech company) to test the CeO ₂ /TiO ₂ nanocomposite hollow spheres obtained above, the SEM figure of gained is shown in Figure 2, can find out the present invention from Figure 2 The obtained product has a hollow spherical structure, that is, its structure is different from that of the CeO ₂ -TiO ₂ composite oxide in the prior art.

Application Example 1

Get 25mL concentration and be that 20mg/L Rhodamine B solution is placed in the 50ml quartz sleeve, add 20mg embodiment _{5 CeO} in the quartz sleeve Ultrasound for 5min.

Take another 25mL rhodamine B solution with a concentration of 20mg/L and place it in a 50ml quartz sleeve without adding CeO ₂ /TiO ₂ composite hollow spheres to do a blank experiment.

Another 25mL rhodamine B solution with a concentration of 20mg/L was placed in a 50ml quartz tube, and the CeO ₂ -TiO ₂ composite oxide of the prior art was added for a control experiment.

Place the quartz sleeve in the BL-GHX photochemical reaction instrument, absorb in the dark for 30min, and take 5ml of the sample. After the adsorption is completed, the photodegradation reaction is carried out under a 600W ultraviolet light source for 60 minutes, and 5ml of samples are taken every 10 minutes.

After centrifuging the sample at 10000r/min for 5min, the supernatant was taken, and the absorbance was measured with a UV-2100 ultraviolet spectrophotometer. The photocatalytic activity of the CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst and the CeO ₂ -TiO ₂ composite oxide of the prior art is shown in Figure 3, and the composite hollow sphere in Figure 3 is the CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst , the composite powder is an existing technology prepared according to the literature (Chiara G, et al. Structural and spectroscopic characterization of CeO ₂ –TiO ₂ mixed oxides[J]. Journal of Materials Chemistry A, 2013, 1, 10918-10926) CeO ₂ -TiO ₂ composite oxide. It can be seen from Fig. 3 that the CeO ₂ /TiO ₂ nanocomposite hollow spheres prepared by the present invention have a strong ability to photodegrade rhodamine B.

In summary, a CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst of the present invention has a uniform particle size, an average particle size of 216nm-580nm, and obvious cavities. Within 60 minutes under a 600W ultraviolet light source, the CeO ₂ / The photodegradation efficiency of TiO ₂ nanocomposite hollow sphere catalyst to 20mg/L rhodamine B solution is 30%, while the photodegradation efficiency of CeO ₂ -TiO ₂ composite oxide in the prior art to 20mg/L rhodamine B solution is 20%. %, that is, a CeO ₂ /TiO ₂ composite hollow sphere catalyst of the present invention, due to its hollow structure, has a 10% improvement in the degradation ability of rhodamine B compared with the solid structure of CeO ₂ -TiO ₂ composite oxide.

The above content is only a basic description of the concept of the present invention, and any equivalent transformation made according to the technical solution of the present invention shall fall within the scope of protection of the present invention.

Claims (2)

1. a CeO ₂ /TiO ₂ nanometer composite hollow sphere catalyst, it is characterized in that described CeO ₂ /TiO ₂ nanometer composite hollow sphere catalyst, at first take polystyrene as template, with tetrabutyl titanate and hexahydrate nitric acid CeO ₂ /TiO ₂ coated polystyrene composite microspheres were prepared by combining sol-gel method and precipitation method with cerium as the wall material, and then calcined at 500-800°C for 3-5 hours to obtain CeO ₂ /TiO ₂ Nanocomposite hollow sphere catalyst; Among them, the amount of polystyrene, tetrabutyl titanate and cerium nitrate hexahydrate is 0.1-0.3g:0.2-8×10 ^-3 mol:1- 6×10 ^-3 mol, the polystyrene particle size is 200-500nm; The CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst is specifically prepared by a method comprising the following steps: (1) After mixing 0.1-0.3g polystyrene, 0.5-2g deionized water, 10-50μL concentrated ammonia water and 20mL absolute ethanol, control the temperature at 60-75℃ and the speed of 300-500r/min for reaction After 2-4h, the reaction solution 1 was obtained; (2) Dissolve 0.2-8×10 ^-3 mol tetrabutyl titanate in 20 mL of absolute ethanol to prepare a tetrabutyl titanate ethanol solution with a concentration of 0.01-0.40 mol/L; Add the ethanol solution of tetrabutyl titanate with a concentration of 0.01-0.40mol/L into the reaction solution 1 obtained in step (1) within 0.5-1h, control the temperature at 60-75°C and the rotation speed at 300-500r/min for reaction 2 -4h, obtain reaction solution 2; (3) Dissolve 1-6×10 ^-3 mol of cerium nitrate hexahydrate in 20 mL of absolute ethanol to prepare a 0.05-0.3 mol/L cerium nitrate ethanol solution; Add the ethanol solution of cerium nitrate with a concentration of 0.05-0.3mol/L into the reaction solution 2 obtained in step (2) within 0.5-1h, control the temperature at 60-75°C, and carry out the reaction at 300-500r/min for 2-4h, Obtain reaction solution 3; The obtained reaction solution 3 was centrifuged, and the obtained precipitate was dried at 60-80° C. for 8-10 h to obtain a light yellow powder; The light yellow powder is calcined at 500-800°C for 3-5h, and naturally cooled to room temperature to obtain the CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst. 2. The CeO ₂ /TiO ₂ nanocomposite hollow sphere catalyst according to claim 1, characterized in that its particle size is 216nm-580nm.