Preparation Of G-C₃N₄-based Composite Material And Its Photocatalytic Performance For Degradation Of Organic Pollutants

With the rapid development of industry and the continuous increase of population,the water pollution caused by organic pollutants has become serious problem.It is urgent to find an efficient water treatment technology to remove organic pollutants from water.In recent years,Semiconductor photocatalytic oxidation is one of the most green and efficient disinfection technologies.It is prepared that because of its high degradation efficiency,environmental friendliness,energy saving and environmental protection,and overcoming the limitations of traditional disinfection methods.Be concerned.The semiconductor photocatalyst has become a research hotspot in recent years because of its ability to provide a"green"path for the full degradation of organic pollutants in water,photolysis of water to produce hydrogen,and carbon dioxide conversion.In order to achieve the high efficiency of photocatalytic degradation of organic pollutants in water.The narrow-band semiconductors are usually used as photocatalysts.These narrow-band semiconductor photocatalysts have certain shortcomings in practical applications,because of their have high recombination rate of photogenerated electrons and holes.Therefore,researchers have been looking for highly efficient photocatalytic semiconductor materials.Among many photocatalytic materials,g-C₃N₄has high chemical and thermal stability,and is widely used in photocatalytic oxidation technology in the environmental field.In order to further expand the application of g-C₃N₄-based visible light-responsive composite photocatalyst in the environmental field.Preparing two highly efficient Ag₂O/P-g-C₃N₄and Ag₃PO₄/P-g-C₃N₄composite photocatalytic materials have been developed.（1）By adjusting the microstructure of g-C₃N₄,using a mixture of melamine and urea at a mass ratio of 1:1 as the precursor.The precursor recombination,isopotential method and in-situ deposition method were used to synthesize Ag₂O/P-g-C₃N₄composite photocatalytic material,（2）select phytic acid as the phosphorus source and urea as the precursor of g-C₃N₄to prepare P-g-C₃N₄,and prepare new and efficient Ag₃PO₄/P-g-C₃N₄by co-precipitation method.The metal Ag medium is formed between the g-C₃N₄,and the tandem configuration significantly enhances the light-induced electron migration.In the first part of the study,the photocatalytic performance of the material was tested by degrading Rh6G and levofloxacin.The Ag₂O/P-g-C₃N₄（2:1）composite material degraded about 99%of Rh6G and 83%of levofloxacin by visible light radiation in 50 min and 120 min,respectively.The microscopic morphology and optical properties of Ag₂O/P-g-C₃N₄composite materials were analyzed by XRD,XPS,SEM,TEM,etc.Based on the experimental and analytical results of different proportions of materials,the degradation mechanism of Ag₂O/P-g-C₃N₄was explained reasonably.In the second part of the study,the photocatalytic properties of the materials were tested by degrading enrofloxacin,methylene blue,methylene orange,and RhB.The P-g-C₃N₄/Ag₃PO₄composite material exhibits strong redox ability and can effectively degrade organic pollutants.The removal of ENF pollutants at 150min is80%,and the removal of MB,MO,RhB pollutants at 70min is 94%,85%,96%.Active species capture experiment and ESR test show that h⁺,·OH,·O2^-are the main active species in the degradation of organic pollution,and based on the calculation and analysis results of the above experiments,the possible mechanism of Ag₃PO₄/P-g-C₃N₄composite material degrading ENF antibiotics.In this paper,two new photocatalysts based on g-C₃N₄are prepared.The modification of g-C₃N₄broadens the response range of visible light,reduces the hole recombination rate of photo-generated electrons,and effectively improves the photocatalytic activity of g-C₃N₄.Therefore,the photocatalyst to efficiently degrade organic pollutants in the water environment,and optimizing the water environment and ecosystem health.