Characterization And Photocatalytic Properties Of Bi₂WO₆ Composite Photocatalyst Synthesized By A Hydrothermal Method

Bi₂WO₆ is a new kind of visible light catalyst,which has excellent light catalytic performance,stable structure and environment friendly.It belongs to N type semiconductor with a direct band gap of 2.7eV,Bi₂WO₆ is considered as a kind of ideal light catalytic material.This paper aims to explore the optimum parameters of Bi₂WO₆ preparation,which has a excellent light catalyst performance.The experiments were conducted at different reaction temperatures,reaction time,pH values and HNO₃ concentrations.And the effect on structure,morphology and light catalytic performance of Bi₂WO₆prepared was studied.Then Bi₂WO₆ doped with rGO and g-C₃N₄ was synthesized at the same experimental parameter and the effect on morphology,structure and photocatalytic properties of different doping content was discussed.The main research of this paper is as follows:?1?The experimental results showed that Bi₂WO₆ photocatalyst was successfully synthesized by hydrothermal method and different experimental parameters all have an strong influence on the structure,morphology Bi₂WO₆ photocatalystand properties.The light catalytic properties measurements show that the optimum parameter is as follows:the content of HNO₃ prepared is 10mL,the pH of the precursor solution is 3,the reaction temperature and time is 160oC and 12h,respectively.?2?By using hydrothermal method,rGO/Bi₂WO₆ composite photocatalyst was prepared by adding a certain amount of GO,and the influence of different GO content on the structure,morphology and properties of the synthesized samples was studied.The result shows that GO can be reduced to rGO in the high temperature and high pressure environment,which is the basis for the synthesis of rGO/Bi₂WO₆composites photocatalyst.The adding of GO has no influence on the structure of Bi₂WO₆,but can change the morphology of the samples.The morphology of flower was observed in part of the samples,which only can be found at the sample prepared at 160oC.And the adding of rGO increases the Bi₂WO₆ the surface area of the samples.The composite state of Bi₂WO₆ and rGO changes from scattered to well-distributed and gathered later.The rGO/Bi₂WO₆ composite photocatalyst synthesized shows the best visible light catalytic performance when the addition content of GO is 5mg.The degradation time of RhB of the sample is 80min.?3?The Bi₂WO₆ was prepared with g-C₃N₄ by using hydrothermal method.After drying,g-C₃N₄/Bi₂WO₆ composite photocatalyst was synthesized by solid sintering method and the effect on structure,morphology,performance of the samples prepared with g-C₃N₄ adding is studies.The results show that g-C₃N₄/Bi₂WO₆ composite photocatalyst was successfully synthesized,the composite state of Bi₂WO₆ and g-C₃N₄ changes with g-C₃N₄ adding content.Bi₂WO₆ accumulated around with g-C₃N₄ first,and then it well-distributed with the g-C₃N₄ and final it sparsely scattered on the surface of g-C₃N₄ sparsely.Performance test result shows that when the adding content of melamine is 3g,g-C₃N₄/Bi₂WO₆ composite photocatalyst perform the best visible light photocatalytic properties.The degradation time of RhB of the sample is85min.