CN110871099A - Ag-containing material3PO4And carboxylated g-C3N4Preparation method of photocatalytic degradation nano-fiber - Google Patents

Abstract

The invention discloses a preparation method of photocatalytic degradation nanofibers containing Ag ₃ PO ₄ and carboxylated g-C ₃ N ₄ . First, chemically oxidize g _- C ₃ N ₄ to generate hydroxyl and carboxyl groups _on its basal plane. In order to further increase the carboxyl group content on the surface of g-C ₃ N ₄ The reaction yields carboxylated g-C ₃ N ₄ . Fully disperse the carboxylated g _- C ₃ N ₄ into water, add silver nitrate to make the silver ions fully adsorbed to the surface of the carboxylated g _{-C 3 N 4} Ag ₃ PO ₄ nanoparticles were generated on the surface. Then, a spinning aid was added to the system and fully dissolved to obtain a spinning solution, and a photocatalytic degradation nanofiber containing Ag ₃ PO ₄ and carboxylated g-C ₃ N ₄ was obtained through an electrospinning process. The nanofibers can be directly used in the wet state or sintered to obtain inorganic nanofibers, both of which have good photocatalytic degradation performance and reuse performance, and have good application prospects in the field of photocatalytic degradation of solid, liquid and gas pollutants.

Description

A kind of preparation method of photocatalytic degradation nanofiber containing Ag3PO4 and carboxylated g-C3N4

technical field

The invention relates to a preparation method of photocatalytic degradation nanofibers containing Ag ₃ PO ₄ and carboxylated gC ₃ N ₄ , belonging to the fields of functional materials, photocatalysis and nanofibers.

The invention relates to the technical fields of photocatalytic degradation, filter membranes, nanofibers and the like. Specifically, it relates to a preparation method of photocatalytic degradation nanofibers containing Ag ₃ PO ₄ and carboxylated gC ₃ N ₄ .

Background technique

Photocatalytic degradation is the use of highly active free radicals generated by radiation and photocatalysts in the reaction system, and then through the addition, substitution, and electron transfer between free radicals and organic pollutants. All pollutants are degraded into inorganic substances. the process of. In recent years, photocatalytic technology has received extensive attention in the field of refractory wastewater treatment and is considered to be one of the most promising technologies for controlling refractory organic pollutants in water bodies. It has been widely used in textiles, dyes, coking, medicine, etc. Treatment of wastewater. The application of photocatalytic degradation to the treatment of industrial wastewater and drinking water has become the focus of related research [J. Membrane. Sci, 2012, 392-393: 192-203]. Among the many semiconductor materials used for photocatalytic degradation, _TiO2 is considered as the most suitable photocatalyst due to its excellent properties such as high activity, high chemical stability, photostability, non-toxicity and low price [J.Hazard.Mater] , 2011, 185:77-85]. In conventional wastewater treatment processes, _TiO2 nanoparticles are usually utilized in the form of suspended systems due to the large surface area of their particles. However, the separation of suspended _TiO2 nanoparticles in wastewater will inevitably increase operating costs and cause secondary pollution, thus greatly limiting its practical application. Due to its wide band gap, the traditional photocatalyst TiO ₂ only responds to ultraviolet light, and this part of the light accounts for less than 5% of sunlight, the utilization rate of visible light is low, and the electron-hole pair recombination rate is high and It has disadvantages such as low quantum efficiency.

The essence of the photocatalytic reaction is a redox reaction. When the semiconductor photocatalytic material is irradiated by light, it will absorb light energy. Once the energy exceeds its threshold, the material will be excited to generate photogenerated electrons (e ^- ) and holes (h ⁺ ), Electrons and holes migrate to the surface of the catalytic material, where the electrons are captured by dissolved oxygen to form superoxide radicals (·O ^2- ), while the holes will be adsorbed on the surface of the catalyst to oxidize water and hydroxide ions to hydroxyl free radicals Base (·OH), both of which have strong oxidizing properties, thus oxidizing the pollutants/bacteria on the surface of the material into CO ₂ and H ₂ O, and finally play the functions of antifouling, sterilization and purification. _gC3N4 is a typical polymer semiconductor, and the CN atoms in its structure are ^sp hybridized to form a highly delocalized π _- conjugated system. Among them, the _Npz orbital constitutes the highest occupied molecular orbital (HOMO) of _gC3N4 , and the Cpz orbital constitutes the lowest unoccupied molecular orbital (LUMO). gC ₃ N ₄ has a very suitable semiconducting band-edge position, which meets the thermodynamic requirements of photo-splitting water for hydrogen production. gC ₃ N ₄ has good thermal and chemical stability, is environmentally friendly, and has no secondary pollution. As a new type of non-metallic photocatalytic material, compared with the traditional TiO ₂ photocatalyst, gC ₃ N ₄ has a wider absorption spectrum, and does not require ultraviolet light and can only play a photocatalytic role under ordinary visible light; at the same time, compared with TiO 2 ₂ , gC ₃ N ₄ can more effectively activate molecular oxygen, generate superoxide radicals for photocatalytic conversion of organic functional groups and photocatalytic degradation of organic pollutants, and is more suitable for indoor air pollution control and organic matter degradation. Ag ₃ PO ₄ is a newly developed visible light catalyst with good visible light catalytic activity. The conduction band energy potential and valence band energy potential of Ag ₃ PO ₄ are 0.45V and 2.9V, respectively, which have a good match with the conduction band energy potential (-1.13V) and valence band energy potential (1.57V) of gC ₃ N ₄ Therefore, the combination of the two can effectively improve the separation efficiency of photogenerated electrons/holes and improve the visible light catalytic activity of the composite material.

Nanofibrous scaffolds prepared by electrospinning have a high surface-to-volume ratio, which can enhance cell adsorption, drug loading, and photocatalytic functions. Electrospinning is the method that has received the most attention in recent years and is most likely to achieve industrialized preparation of nanofibers. Electrospun fiber membranes have small fiber diameters, large specific surface areas, and moderate porosity, and have been widely used in various engineering and various human tissues. Electrospinning was first discovered and patented by Formhals in Germany in 1934.

The invention discloses a preparation method of photocatalytic degradation nanofibers containing Ag ₃ PO ₄ and carboxylated gC ₃ N ₄ . Firstly, _gC3N4 is chemically oxidized to generate hydroxyl and carboxyl groups _on its basal plane. In order to further increase the carboxyl group content _on the surface of _gC3N4 , the chemically oxidized _gC3N4 is reacted with chloroacetic _acid to obtain carboxylated _gC3N4 . N ₄ . Fully disperse carboxylated gC ₃ N ₄ in water, add silver nitrate to make silver ions fully adsorbed to the surface of carboxylated gC ₃ N ₄ , and then add excess soluble phosphate to generate Ag ₃ PO ₄ on the surface of carboxylated gC ₃ N ₄ Nanoparticles. Then the spinning auxiliaries were added into the system and fully dissolved to obtain the spinning solution, and the photocatalytic degradation nanofibers containing Ag ₃ PO ₄ and carboxylated gC ₃ N ₄ were obtained through the electrospinning process. The nanofibers can be directly used in the wet state or sintered to obtain inorganic nanofibers, both of which have good photocatalytic degradation performance and reuse performance, and have good application prospects in the field of photocatalytic degradation of solid, liquid and gas pollutants.

SUMMARY OF THE INVENTION

In view of the deficiencies of the prior art, the technical problems to be solved by the present invention are that the traditional photocatalyst TiO ₂ has a wider band gap, only responds to ultraviolet light, has a low utilization rate of visible light, and has a high electron-hole pair recombination rate and has quantum low efficiency, etc.

The technical solution of the present invention to solve the problems of the traditional photocatalyst _TiO2 having a wide band gap, only responding to ultraviolet light, low utilization rate of visible light, high electron-hole pair recombination rate and low quantum efficiency is to provide a A preparation method of photocatalytic degradation nanofibers containing Ag ₃ PO ₄ and carboxylated gC ₃ N ₄ .

The invention provides a preparation method of photocatalytic degradation nanofibers containing Ag ₃ PO ₄ and carboxylated gC ₃ N ₄ , which is characterized by comprising the following steps:

a) Chemically oxidize gC ₃ N ₄ with a mixed aqueous solution of potassium dichromate and sulfuric acid, and introduce hydroxyl and carboxyl groups _on the gC ₃ N ₄ base surface _. The gC ₃ N ₄ reacted with chloroacetic acid to generate carboxylated gC ₃ N ₄ , centrifuged and washed to remove residual inorganic salts and acids, and freeze-dried to obtain carboxylated gC ₃ N ₄ solid powder; control the concentration of chloroacetic acid, the reaction temperature and the reaction The time makes the mass percentage content of carboxyl groups in the carboxylated gC ₃ N ₄ to be 0.1%-10%;

b) Disperse the carboxylated gC ₃ N ₄ solid powder obtained in step a) into deionized water, adjust the pH value to be weakly alkaline, ultrasonically disperse the carboxylated gC ₃ N ₄ in water uniformly, and control the carboxylated gC ₃ N ₄ The mass percentage concentration in water is 0.01%-5%; silver nitrate aqueous solution with a mass percentage concentration of 0.1%-5% is added to the aqueous dispersion of carboxylated gC ₃ N ₄ to make silver ions fully adsorbed to the carboxylated gC ₃ N ₄ surface, and then add excess soluble phosphate to generate Ag ₃ PO ₄ nanoparticles on the surface of carboxylated gC ₃ N ₄ to obtain a mixture aqueous solution containing carboxylated gC ₃ N ₄ and Ag ₃ PO ₄ nanoparticles;

c) Add spinning aid and sodium alginate to the mixture aqueous solution containing carboxylated gC ₃ N ₄ and Ag ₃ PO ₄ nanoparticles obtained in step b) and fully dissolve to obtain spinning solution, spinning aid and alginic acid The mass percentage of sodium is 0.5-5:0.5-10;

d) preparing an aqueous solution of soluble calcium salt with a mass percentage concentration of 0.2%-20% as a coagulation bath;

e) The spinning solution obtained in step b) is electrospinned to obtain nanofibers; the nanofibers are soaked in the coagulation bath obtained in step d) for 5-240min, and the soluble calcium salt reacts with sodium alginate to form seaweed At the same time, the calcium alginate hydrogel is also cross-linked with the carboxyl groups on the carboxylated gC ₃ N ₄ to generate an organic-inorganic hybrid structure, coupled with the physical enhancement of the carboxylated gC ₃ N ₄ , thereby improving the calcium alginate hydrogel. The mechanical strength of the gel reduces its swelling performance; at the same time, the soluble calcium salt reacts with the excess soluble phosphate in the nanofibers to form calcium phosphate, which can prevent the loss of Ag ₃ PO ₄ ; finally, soak and wash in deionized water to remove the remaining nanofibers. Inorganic salt, a photocatalytic degradation _nanofiber containing _Ag3PO4 and carboxylated _gC3N4 was obtained _.

The method for preparing photocatalytic degradation nanofibers containing Ag ₃ PO ₄ and carboxylated gC ₃ N ₄ according to the present invention is characterized in that the soluble phosphate is diammonium hydrogen phosphate, disodium hydrogen phosphate, hydrogen phosphate Any one or two or more mixtures of dipotassium, tripotassium phosphate, and trisodium phosphate; the spinning aid is any one or two of polyvinyl alcohol, polyoxyethylene ether, and polyacrylamide mixture; the soluble calcium salt is any one or a mixture of two or more selected from calcium chloride, calcium nitrate, calcium dihydrogen phosphate and calcium gluconate.

The photocatalytic degradation nanofibers containing Ag ₃ PO ₄ and carboxylated gC ₃ N ₄ prepared by the invention can be directly used in wet state, and can also be sintered to obtain inorganic nano fibers for use, and both have good photocatalytic degradation and reuse performance. , has good application prospects in photocatalytic degradation of solid, liquid and gaseous pollutants.

Detailed ways

Specific embodiments of the present invention are described below, but the present invention is not limited by the embodiments.

Example 1.

a) Chemically oxidize gC ₃ N ₄ with a mixed aqueous solution of potassium dichromate and sulfuric acid, and introduce hydroxyl and carboxyl groups _on the gC ₃ N ₄ base surface _. The gC ₃ N ₄ reacted with chloroacetic acid to generate carboxylated gC ₃ N ₄ , centrifuged and washed to remove residual inorganic salts and acids, and freeze-dried to obtain carboxylated gC ₃ N ₄ solid powder; control the concentration of chloroacetic acid, the reaction temperature and the reaction The time makes the mass percentage content of carboxyl groups in carboxylated gC ₃ N ₄ to be 0.1%;

b) Disperse the carboxylated gC ₃ N ₄ solid powder obtained in step a) into deionized water, adjust the pH value to be weakly alkaline, ultrasonically disperse the carboxylated gC ₃ N ₄ in water uniformly, and control the carboxylated gC ₃ N ₄ The mass percentage concentration in water is 0.01%; the 0.1% mass percentage concentration of silver nitrate aqueous solution is added to the aqueous dispersion of carboxylated gC ₃ N ₄ to make silver ions fully adsorbed to the surface of carboxylated gC ₃ N ₄ , and then an excess amount is added. Diammonium hydrogen phosphate generates Ag ₃ PO ₄ nanoparticles on the surface of carboxylated gC ₃ N ₄ to obtain a mixture aqueous solution containing carboxylated gC ₃ N ₄ and Ag ₃ PO ₄ nanoparticles;

c) Add polyvinyl alcohol and sodium alginate to the mixture aqueous solution containing carboxylated gC ₃ N ₄ and Ag ₃ PO ₄ nanoparticles obtained in step b) and fully dissolve to obtain spinning solution, the mass percentage of polyvinyl alcohol and sodium alginate is 0.5:0.5;

d) prepare an aqueous solution of calcium chloride with a mass percentage concentration of 0.2% as a coagulation bath;

e) using the spinning solution obtained in step b) to obtain nanofibers by electrospinning; placing the nanofibers in the coagulation bath obtained in step d) and soaking for 5 minutes, the soluble calcium salt reacts with sodium alginate to generate calcium alginate At the same time of the hydrogel, it is also cross-linked with the carboxyl groups _on the carboxylated _gC3N4 to generate an organic _- inorganic hybrid structure, coupled with the physical enhancement of the carboxylated _gC3N4 , thereby improving the calcium alginate hydrogel. At the same time, the soluble calcium salt reacts with excess diammonium hydrogen phosphate in the nanofibers to form calcium phosphate, which can prevent the loss of Ag ₃ PO ₄ ; finally, soak and wash in deionized water to remove the residual inorganic in the nanofibers. salt, resulting in a photocatalytically degraded _nanofiber containing _Ag3PO4 and carboxylated _{gC3N4 .}

Example 2.

a) Chemically oxidize gC ₃ N ₄ with a mixed aqueous solution of potassium dichromate and sulfuric acid, and introduce hydroxyl and carboxyl groups _on the gC ₃ N ₄ base surface _. The gC ₃ N ₄ reacted with chloroacetic acid to generate carboxylated gC ₃ N ₄ , centrifuged and washed to remove residual inorganic salts and acids, and freeze-dried to obtain carboxylated gC ₃ N ₄ solid powder; control the concentration of chloroacetic acid, the reaction temperature and the reaction The time makes the mass percentage content of carboxyl groups in the carboxylated gC ₃ N ₄ to be 2.5%;

b) Disperse the carboxylated gC ₃ N ₄ solid powder obtained in step a) into deionized water, adjust the pH value to be weakly alkaline, ultrasonically disperse the carboxylated gC ₃ N ₄ in water uniformly, and control the carboxylated gC ₃ N ₄ The mass percentage concentration in water is 2.5%; the aqueous solution of silver nitrate with a mass percentage concentration of 5% is added to the aqueous dispersion of carboxylated gC ₃ N ₄ to make the silver ions fully adsorbed to the surface of carboxylated gC ₃ N ₄ , and then an excess amount is added. disodium hydrogen phosphate, Ag ₃ PO ₄ nanoparticles are generated on the surface of carboxylated gC ₃ N ₄ to obtain a mixture aqueous solution containing carboxylated gC ₃ N ₄ and Ag ₃ PO ₄ nanoparticles;

c) adding polyoxyethylene ether and sodium alginate to the mixture aqueous solution containing carboxylated gC ₃ N ₄ and Ag ₃ PO ₄ nanoparticles obtained in step b) and fully dissolving to obtain spinning solution, polyoxyethylene ether and alginic acid The mass percentage of sodium is 0.5:1;

d) preparing an aqueous solution of calcium nitrate with a mass percentage concentration of 5.0% as a coagulation bath;

e) using the spinning solution obtained in step b) to obtain nanofibers by electrospinning; placing the nanofibers in the coagulation bath obtained in step d) for 120 min, and the soluble calcium salt reacts with sodium alginate to generate calcium alginate At the same time of the hydrogel, it is also cross-linked with the carboxyl groups _on the carboxylated _gC3N4 to generate an organic _- inorganic hybrid structure, coupled with the physical enhancement of the carboxylated _gC3N4 , thereby improving the calcium alginate hydrogel. At the same time, the soluble calcium salt reacts with the excess disodium hydrogen phosphate in the nanofibers to form calcium phosphate, which can prevent the loss of Ag ₃ PO ₄ ; finally, soak and wash in deionized water to remove the residual inorganic in the nanofibers. salt, resulting in a photocatalytically degraded _nanofiber containing _Ag3PO4 and carboxylated _{gC3N4 .}

Example 3.

a) Chemically oxidize gC ₃ N ₄ with a mixed aqueous solution of potassium dichromate and sulfuric acid, and introduce hydroxyl and carboxyl groups _on the gC ₃ N ₄ base surface _. The gC ₃ N ₄ reacted with chloroacetic acid to generate carboxylated gC ₃ N ₄ , centrifuged and washed to remove residual inorganic salts and acids, and freeze-dried to obtain carboxylated gC ₃ N ₄ solid powder; control the concentration of chloroacetic acid, the reaction temperature and the reaction The time makes the mass percentage content of carboxyl groups in the carboxylated gC ₃ N ₄ to be 10%;

b) Disperse the carboxylated gC ₃ N ₄ solid powder obtained in step a) into deionized water, adjust the pH value to be weakly alkaline, ultrasonically disperse the carboxylated gC ₃ N ₄ in water uniformly, and control the carboxylated gC ₃ N ₄ The mass percentage concentration in water is 5%; the aqueous solution of silver nitrate with a mass percentage concentration of 1% is added to the aqueous dispersion of carboxylated gC ₃ N ₄ , so that silver ions are fully adsorbed to the surface of carboxylated gC ₃ N ₄ , and then an excess amount is added. Dipotassium hydrogen phosphate and tripotassium phosphate generate Ag ₃ PO ₄ nanoparticles on the surface of carboxylated gC ₃ N ₄ to obtain a mixture aqueous solution containing carboxylated gC ₃ N ₄ and Ag ₃ PO ₄ nanoparticles;

c) adding polyacrylamide and sodium alginate to the mixture aqueous solution containing carboxylated gC ₃ N ₄ and Ag ₃ PO ₄ nanoparticles obtained in step b) and fully dissolving to obtain a spinning solution, the mixture of polyacrylamide and sodium alginate The mass percentage is 1:10;

d) preparing an aqueous solution of calcium dihydrogen phosphate with a mass percentage concentration of 20% as a coagulation bath;

e) Electrospinning the spinning solution obtained in step b) to obtain nanofibers; put the nanofibers in the coagulation bath obtained in step d) and soak for 240min, and the soluble calcium salt reacts with sodium alginate to generate calcium alginate At the same time of the hydrogel, it is also cross-linked with the carboxyl groups _on the carboxylated _gC3N4 to generate an organic _- inorganic hybrid structure, coupled with the physical enhancement of the carboxylated _gC3N4 , thereby improving the calcium alginate hydrogel. At the same time, the soluble calcium salt reacts with excess dipotassium hydrogen phosphate and tripotassium phosphate in the nanofibers to form calcium phosphate, which can prevent the loss of Ag ₃ PO ₄ ; finally, the nanofibers are removed by soaking and washing in deionized water. Residual inorganic salts were obtained to obtain a photocatalytically degraded nanofiber containing Ag ₃ PO ₄ and carboxylated gC ₃ N ₄ .

Example 4.

a) Chemically oxidize gC ₃ N ₄ with a mixed aqueous solution of potassium dichromate and sulfuric acid, and introduce hydroxyl and carboxyl groups _on the gC ₃ N ₄ base surface _. The gC ₃ N ₄ reacted with chloroacetic acid to generate carboxylated gC ₃ N ₄ , centrifuged and washed to remove residual inorganic salts and acids, and freeze-dried to obtain carboxylated gC ₃ N ₄ solid powder; control the concentration of chloroacetic acid, the reaction temperature and the reaction The time makes the mass percentage content of carboxyl groups in the carboxylated gC ₃ N ₄ to be 1%;

b) Disperse the carboxylated gC ₃ N ₄ solid powder obtained in step a) into deionized water, adjust the pH value to be weakly alkaline, ultrasonically disperse the carboxylated gC ₃ N ₄ in water uniformly, and control the carboxylated gC ₃ N ₄ The mass percentage concentration in water is 1%; the aqueous solution of silver nitrate with a mass percentage concentration of 2% is added to the aqueous dispersion of carboxylated gC ₃ N ₄ , so that silver ions are fully adsorbed to the surface of carboxylated gC ₃ N ₄ , and then an excess amount is added. Trisodium phosphate, Ag ₃ PO ₄ nanoparticles are generated on the surface of carboxylated gC ₃ N ₄ to obtain a mixture aqueous solution containing carboxylated gC ₃ N ₄ and Ag ₃ PO ₄ nanoparticles;

c) adding polyoxyethylene ether and sodium alginate to the mixture aqueous solution containing carboxylated gC ₃ N ₄ and Ag ₃ PO ₄ nanoparticles obtained in step b) and fully dissolving to obtain spinning solution, polyoxyethylene ether and alginic acid The mass percentage of sodium is 5:10;

d) preparing an aqueous solution of calcium gluconate with a mass percentage concentration of 5% as a coagulation bath;

e) using the spinning solution obtained in step b) to obtain nanofibers by electrospinning; placing the nanofibers in the coagulation bath obtained in step d) for 60 min, and the soluble calcium salt reacts with sodium alginate to generate calcium alginate At the same time of the hydrogel, it is also cross-linked with the carboxyl groups _on the carboxylated _gC3N4 to generate an organic _- inorganic hybrid structure, coupled with the physical enhancement of the carboxylated _gC3N4 , thereby improving the calcium alginate hydrogel. At the same time, the soluble calcium salt reacts with the excess trisodium phosphate in the nanofibers to form calcium phosphate, which can prevent the loss of Ag ₃ PO ₄ ; finally, soak and wash in deionized water to remove the residual inorganic salts in the nanofibers , a photocatalytic degradation nanofiber containing Ag ₃ PO ₄ and carboxylated gC ₃ N ₄ was obtained.

Claims (5)

1. Ag-containing material₃PO₄And carboxylated g-C₃N₄The preparation method of the photocatalytic degradation nano-fiber is characterized by comprising the following steps:

a) using a mixed aqueous solution of potassium dichromate and sulfuric acid for g-C₃N₄Is subjected to chemical oxidation at g-C₃N₄Introduction of hydroxyl and carboxyl on basal plane to further increase g-C₃N₄Carboxyl content of the surface, g-C after chemical oxidation₃N₄Reaction with chloroacetic acid to form carboxylated g-C₃N₄Centrifuged and washedRemoving residual inorganic salts and acids, and freeze drying to obtain carboxylated g-C₃N₄A solid powder; controlling the concentration of chloroacetic acid, reaction temperature and reaction time to carboxylation g-C₃N₄The mass percentage content of the carboxyl is 0.1-10%;

b) carboxylating g-C obtained in step a)₃N₄Dispersing solid powder into deionized water, adjusting pH to alkalescence, and performing ultrasonic treatment to carboxylate g-C₃N₄Uniformly dispersed in water, controlling carboxylation g-C₃N₄The mass percentage concentration in water is 0.01-5%; in carboxylation of g-C₃N₄Adding silver nitrate water solution with the mass percentage concentration of 0.1-5% into the water dispersion liquid to fully adsorb silver ions to the carboxylated g-C₃N₄Surface, then adding excess soluble phosphate, carboxylating g-C₃N₄Surface generation of Ag₃PO₄Nanoparticles to obtain carboxylated g-C-containing₃N₄And Ag₃PO₄An aqueous mixture of nanoparticles;

c) to the carboxylated g-C-containing product obtained in step b)₃N₄And Ag₃PO₄Adding a spinning auxiliary agent and sodium alginate into the aqueous solution of the mixture of the nano particles, and fully dissolving to obtain a spinning solution, wherein the mass percentage of the spinning auxiliary agent to the sodium alginate is 0.5-5: 0.5-10;

d) preparing an aqueous solution of soluble calcium salt with the mass percentage concentration of 0.2-20% as a coagulating bath;

e) obtaining the nano-fiber from the spinning solution obtained in the step b) by adopting an electrostatic spinning process; soaking the nano-fiber in the coagulating bath obtained in the step d) for 5-240min, reacting the soluble calcium salt with sodium alginate to generate calcium alginate hydrogel, and simultaneously reacting with carboxylated g-C₃N₄The carboxyl groups on the surface are crosslinked to generate an organic-inorganic hybrid structure, and carboxylation g-C is added₃N₄The physical enhancement function of the calcium alginate hydrogel, thereby improving the mechanical strength of the calcium alginate hydrogel and reducing the swelling performance of the calcium alginate hydrogel; meanwhile, soluble calcium salt reacts with excessive soluble phosphate in the nano-fiber to generate calcium phosphate, which can prevent Ag₃PO₄Loss; finally, the deionized water is usedSoaking in water, washing to remove residual inorganic salt in nanofiber to obtain the product containing Ag₃PO₄And carboxylated g-C₃N₄The photocatalytic degradation of the nanofibers.

2. Ag-containing alloy according to claim 1₃PO₄And carboxylated g-C₃N₄The preparation method of the photocatalytic degradation nano-fiber is characterized in that the soluble phosphate is any one or a mixture of two or more of diammonium hydrogen phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate and trisodium phosphate.

3. Ag-containing alloy according to claim 1₃PO₄And carboxylated g-C₃N₄The preparation method of the photocatalytic degradation nano-fiber is characterized in that the spinning auxiliary agent is any one or a mixture of polyvinyl alcohol, polyoxyethylene ether and polyacrylamide.

4. Ag-containing alloy according to claim 1₃PO₄And carboxylated g-C₃N₄The preparation method of the photocatalytic degradation nano-fiber is characterized in that the soluble calcium salt is any one or a mixture of two or more of calcium chloride, calcium nitrate, calcium dihydrogen phosphate and calcium gluconate.

5. Ag-containing material₃PO₄And carboxylated g-C₃N₄The preparation method of the photocatalytic degradation nanofiber is characterized in that the nanofiber can be directly used in a wet state and can also be sintered to obtain inorganic nanofibers for use, and the inorganic nanofibers have good photocatalytic degradation and reusability and have good application prospects in the aspect of photocatalytic degradation of solid, liquid and gas pollutants.