Preparation,Modification And Application Of Bismuth Phosphate

Environmental pollution is a problem caused by the rapid development of human society in recent years.Environmental problems are related to the survival environment of human beings and the sustainable development of economy and society.Using sunlight to degrade organic pollutants in water through photocatalysts is a clean,green and feasible solution.Bismuth-based photocatalysts have been favored by many scholars in recent years because of their special energy band structure.Bismuth phosphate is easy to prepare and pollution-free.Compared with other photocatalysts,it has a wider band gap and can only absorb and use part of the ultraviolet light.The ultraviolet light is only about 4%of the solar energy.thus,there is an urgent need to modify the bismuth phosphate to improve its photocatalytic properties in the application of practical production and life.This article focuses on the preparation,modification and degradation of bismuth phosphate,the main content and results are as follows:（1）Three different morphologies of bismuth phosphate were prepared by the direct preparation method,hydrothermal method,and hydrothermal-calcination method.Through the simulated photocatalytic degradation of basic green experiment,the degradation effect of the directly prepared bismuth phosphate was not good,the conclusion that the degradation effect of bismuth phosphate prepared by hydrothermal method is slightly higher than that of bismuth phosphate prepared by hydrothermal-calcination method;（2）The sol-gel method is used to combine the hydrothermal bismuth phosphate with titanium dioxide,and then calcined to prepare TiO₂/BiPO₄heterojunction,its photocatalytic performance is greatly improved compared with the hydrothermal-calcined bismuth phosphate;（3）Using urea as a precursor,prepared photocatalysts with g-C₃N₄doping content of1.69%,3.33%,7.94%,and 14.71%named as g-C₃N₄/TiO₂/BiPO₄.Degradation of alkaline malachite green experiment showed that,when the content of g-C₃N₄is 1.69%,the performance of g-C₃N₄photocatalyst is better.（4）Using Ag₂O as a precursor,ultrasound-assisted preparation of photocatalysts with Ag doping content of 0.1%,0.25%,0.49%,and 0.98%named as Ag/TiO₂/BiPO₄.The experiment of degrading alkaline malachite green showed that,the photocatalyst with Ag content of 0.25%has better performance;（5）Ultrasound-assisted,sol-gel method is used to uniformly mix and ultrasound four substances prepared by urea,Ag₂O,butyl phthalate,and hydrothermal method,to become a titanium gel,and then calcined to obtain Ag/g-C₃N₄/TiO₂/BiPO₄with g-C₃N₄content g-C₃N₄content 1.69%and Ag content 0.25%;（6）The influence factors and process optimization conditions of Ag/g-C₃N₄/TiO₂/BiPO₄ degrading alkaline malachite green were explored by single factor test and response surface optimization experiment;And the single factor test and orthogonal test were used to explore degradation and process optimization conditions of methylene blue on Ag/g-C₃N₄/TiO₂/BiPO₄.（7）The degradation mechanisms of malachite green and methylene blue on Ag/g-C₃N₄/TiO₂/BiPO₄were investigated by capture experiments.The experiment results showed that the main active substance of Ag/g-C₃N₄/TiO₂/BiPO₄photocatalyst degradation malachite green was·OH,and the main active substances that degrade methylene blue were·OH and·O₂^-.