Construction Of Surface Active Sites Of Photocatalysts And Their Photocatalytic Properties

With the rapid development of science and human society,the environmental problems and energy crisis of human habitation have become the focus of attention all over the world.At present,semiconductor photocatalysis technology can use solar energy for environmental purification and solar fuel power generation.Therefore,it has attracted widespread attention from researchers around the world.The core of photocatalysis technology is the preparation of photocatalysts.Improving the photocatalytic performance of photocatalysis is the most effective means to improve the development of photocatalyst technology.So the key to solving the problem of improving photocatalysis is to develop stable,efficient,and green photocatalysts.In recent years,many photocatalysts have been developed to address environmental and energy crises.However,many photocatalysts exhibit low performance due to their photon absorption efficiency and carrier separation efficiency being too low,so these two problems are the core problems faced by photocatalysts.Therefore,improving the performance of photocatalyst is a serious problem we face.The purpose of this paper is to construct a stable,high-efficiency,green and non-toxic visible light photocatalyst by constructing different active sites on the surface of photocatalyst,exploring the method of constructing surface active sites and photocatalytic mechanism.This paper systematically introduces the basic content of photocatalysis,the catalytic principle of photocatalyst,and comprehensively describes the research status of photocatalyst.Oxygen defects,precious metal loading,and Transition metal disulfides were prepared in detail as a preparation method for surface active sites.Combined with the characterization test methods of XRD,SEM,TEM,XPS,DRS,PL,etc.,the reaction mechanism is theoretically calculated by the transition state,the density of the split wave state,the adsorption energy and the charge transfer amount,and the structure and light of the material after the surface active site is constructed.Catalytic performance has been studied and explored in depth.In this paper,the application performance of three kinds of surface active sites to optical catalysts was studied.First,by introducing the surface active sites of oxygen defects on the surface of bismuth chloride?BiOCl?,the effects of oxygen defects on photocatalytic CO₂ transformation were studied,the generation selectivity of CO was more than 90%,and the BiOCl with oxygen defects on the surface could be converted to 16.76?mol g^-1 after 1 hours of ultraviolet visible light irradiation,about 2.9 times higher than that of BiOCl(5.88?mol g^-1)without oxygen defects.After 1 hours of visible light???420nm?irradiation,BiOCl with oxygen defects also showed the light activity produced by CO(4.15?mol g^-1).However,for BiOCl without oxygen defects,only a small amount of CO(0.36?mol g^-1)can be detected after visible light exposure.The second is the load of precious metal Platinum?Pt?on the surface of different photocatalyst,the results of photocatalytic performance test can be seen,the CO production of TiO₂,g-C₃N₄ and BiOBr is 2.30,6.56 and 1.86?mol g^-1 respectively.However,when the 1%Pt was loaded onto the surface of three photocatalyst,none of the three semiconductor inorganic photocatalysts detected the CO signal,and the amount of CH₄ produced increased as the illumination time increased.The amount of CH₄ produced by Pt-TiO₂,Pt-g-C₃N₄ and Pt-BiOBr three Photocatalyst was 153.04,8.30 and 2.34?mol g^-1,respectively.The results show that after the Pt load on the surface of the photocatalyst,three kinds of catalyst photocatalytic reduction CO₂ become CH₄ yield and selectivity,especially the selectivity of the CH₄ is increased to nearly 100%.Third,the ReS₂ as a catalyst load on the CdS surface for photocatalytic decomposition of aquatic hydrogen research,in the visible light irradiation,Na₂S-Na₂SO₃ as the existence of sacrificial electronic donor,pure CdS and pure ReS₂ show a fairly low photocatalytic activity(CdS is 3.84?mol h^-1,ReS₂ is 2?mol h^-1).After the ReS₂ of the load 1wt%,high photocatalytic decomposition of the production activity of the aquatic H₂ can be achieved(487.14?mol h^-1),which is about 127 times times higher than pure CdS.