Enhanced Photocatalytic Effect On Interface In Two-dimensional Graphene-like Materials Hydrid With Potassium Niobate

The contradiction between energy supply and environmental pollution has become the biggest problem in the current world where humans live in nature harmony.Photocatalysis is considered to be one of the most powerful ways to solve this problem.In recent years,Potassium niobate has been developed as an efficient photocatalyst,and two-dimensional material hydribtion have proven to be an effective method to enhancing photocatalytic capabilities.Therefore,the first-principles method is used to study the photocatalytic properties of the composite interface of potassium niobate and graphene-like two-dimensional materials.The existing experimental results are interpreted and a brand-new high-efficiency photocatalyst is designed.More importantly,explore the factors which enhance photocatalytic effects and the role of two-dimensional materials in enhancing photocatalytic effects.Firstly,KNb O₃?100?surface modification with three RGO sheets of different reductivity is investigated using first-principles calculations,revealing that increasing RGO reductivity enhances the photocatalytic performance of KNb O₃?100?/RGO nanocomposites.In contrast to Ce O₂/RGO nanocomposites,the O atoms of RGO inhibit the photoactivity of KNbO₃/RGO nanocomposites by restraining the effect of inducing a red shift of the corresponding photocatalytic absorption spectra by C 2p states.Increased RGO reductivity extends its absorption edge to the visible light region of the optical absorption and also promotes charge transfer from the KNb O₃?100?surface to RGO sheets,in contrast to the behavior observed for g-C₃N₄/RGO composites.Overall,this work provides a reasonable explanation of controversial experimental results obtained previously,paving the way to the development of highly efficient RGO-based photocatalysts and promoting further photocatalytic applications of KNb O₃/RGO nanocomposites.Secondly,taking Sr Ti O₃?STO?/Mo S₂ heterostructures as an example,the Mo S₂monolayer acts as a sensitizer,co-catalyst and charge conduction medium in photocatalytic hydrogen production,verified by the explore of the KNb O₃?KNO?/Mo S₂ heterostructures.The contribution of Mo 4d states to the CBM or VBM reduce all nanocomposites band gap at least 0.6 e V,enhancing the optical absorptions of STO/Mo S₂ and KNO/Mo S₂ nanocomposites 2³ times larger than that of the STO and KNO surface respectively,indicating that the monolayer Mo S₂is an effective sensitizer.Comparing with STO/GR or KNO/GR nanocomposites,the charge transfer is increasing in STO/Mo S₂ or KNO/Mo S₂ nanocomposites for a smaller equilibrium distance.The dual role of monolayer MoS₂ is expected to arise in other Mo S₂-based nanocomposites.This work rationalizes the existing experimental results and paves the way for developing highly efficient Mo S₂-based photocatalysts.Finally,the electronic structure and photocatalytic properties of KNO/IV?IV=Si,Ge,St?composites were predicted.The composite of Si,Ge and St successfully extended the optical absorption region of KNO/IV?IV=Si,Ge,St?composites to the visible region,which effectively enhanced the photocatalytic activity of the composites.In addition,the role of charge carriers of Si,Ge,and St layers will reduce the recombination of electron-hole pairs in the photocatalytic process and effectively promote the progress of photocatalytic reactions.It can be predicted that KNO/IV?IV=Si,Ge,St?composites may have a wide range of applications in the field of photocatalysis.