Study On The Synthesis Of Bentonite-Bi₂WO₆ Photocatalyst And Its Photocatalytic Activity Driven By Visible Light Irradiation

photocatalysis technological is an environment-friendly technology,it has many superiorities in the area of photodegradation of pollution like low cost and non-pollution,however,it still has disadvantage like can't make full use of visible-light.Therefore,developing new form of visible-light photocatalysis is an important topic which deserve careful study.Bi₂WO₆ is a new kind of photocatalyst which is widely researched recently,and as we know,bentonite is a kind of material with large specific surface area which coule improve the stablility and efficiency of photocatalysis,thus,we consider compositing them and prepared Bentonite-Bi₂WO₆ which could improve the charge separation efficiency and enhance the photocatalysis efficiency.And then,we use RhB as probe pollutants,studying the effect of compound method to its photocatalytic activity.Bentonite-Bi₂WO₆ compound photocatalyst has been successfully synthesized by Bentonite,Bi?NO3?3·5H2O and?NH4?10W12O41 through hydrothermal process,and the compound was characterized by XRD,SEM,TEM,UV-vis DRS and BET surface area analysis,what shows that the main crystal form is orthorhombic of Bi₂WO₆,the absorption of visible light was enhanced,and the surface area became larger.Using RhB as probe pollutant carried out visible light catalytic experiment,and found the optimal synthetic condition of Bentonite-Bi₂WO₆ was selected as:m?Bentonite?/m?Bi₂WO₆?=0.2:1,the pH value of hydrothermal precursor = 3.0,hydrothermal synthetic temperature = 160 ?.the photocatalytic activity of Bentonite-Bi₂WO₆ compound photocatalyst is better compared to the pure Bi₂WO₆.Using Bentonite-Bi₂WO₆ compound photocatalyst synthesised at the optimal conditions to make visible-light photocatalytic degradation of RhB experiments,and we could draw several conclusions:After visible-light illumination for 2 hours,the decolorization rate of 40 mg/L RhB solution could reach about 97%;the decolorization rate of RhB solution decreased while the solution concentration is increasing among 20?80mg/L.photocatalyst has a higher degradation efficency for RhB solution in acidic condtions;Adding some of H2O2 could promote the degradation of RhB;salt like NaCl will interfere the degradation of RhB;Repeated use experiments show that Bentonite-Bi₂WO₆ compound photocatalyst has good stability and could be used repeatedly.In the degradation experiments of malachite green and crystal violet,the new visible-light photocatalytic material of Bentonite-Bi₂WO₆ shows that it has splendid photocatalytic activity:the decolorization rate could reach about 95%after visible-light illumination for 3 hour for 20 mg/L malachite green,and the decolorization rate could reach about 94%after visible-light illumination for 6 hour for 15 mg/L crystal violet with.This study of the topic will further widen the Bentonite and Bi₂WO₆ photocatalyst research field,and the results have certain guiding significance in the aspect of photocatalytic degradation of organic pollutants.