Design And Photocatalytic Properties Of Cu₂O Based Composites

Cuprous oxide-based semiconductor nanomaterials have shown many unique properties,such as good catalytic,optical and electrical properties. Cu₂ O is an intrinsic p-type semiconductor with a direct band gap of around 2.2 eV, Cu₂ O own a high absorption coefficient and high theoretical photoelectric conversion efficiency in the visible light region of solar spectrum,so it has high application value in the field of catalysis.Since its hydrogen production performance has been reported,cuprous oxide-based compound materials have received widespread concerned,they have become important catalyst materials to deal with the problems of air pollution,industrial and domestic waste water.The composites with nanoscale not only have the properties of the single material,but also possess the unique properties of the single material do not have.Because of the synergy between the components can enhance the performance of a single material,or produce new properties.In this paper,we adopt a simple hydrothermal method and water bath method,we can prepare Cu₂ O crystal with different morphologies and its compound,by controlling the morphology and active surface of Cu₂ O crystals,selection of chemical composition of complex to achieve the best catalytic performance.The effects of composition,morphology,structure and chemical composition on the properties of the composites are investigated.The main research contents are as follows:1. Cu₂ O crystals with different morphologies and uniform sizes were prepared by water bath,subsequently,the ZnO nanoparticles were grown on the surface of Cu₂ O crystals through hydrothermal method with different content,thus, Cu₂O/ZnO heterojunctions with different Zn/Cu molar ratios were obtained,this synthesis method of Cu₂O/ZnO heterojunction is simple and has good catalytic performance.When combined ZnO nanoparticles with appropriate proportion,without affecting the original catalytic performance of Cu₂ O active surface,the band structure of ZnO and Cu₂ O can be matched reasonably,which promote the separation of electron-hole pairs,and the photocatalytic performance also be improved.The results show that the mole ratio of Cu/Zn at 3/1 have the best photocatalytic performance,it also show the higher carrier lifetime and photocurrent intensity,besides,the effect of different active species produced by visible-light to the photocatalytic performance also be studied.2.Synthesis of Cu₂O/rGO composites by a simple one-step method,the material is let Cu₂ O crystal particles grow on the surface of 2D-dimensional reduction graphene oxide.The composites obtained by this method combine the excellent photocatalytic performance of Cu₂ O and the good electron transport property of2D-rGO sheets,this combination mode is favor to the fast separation and transfer of photo-generate carriers produced under visible-light irradiation,which can achieve the purpose to accelerate photocatalytic degradation of organic dye.3.Depending on Pearson's hard and soft acid-base?HSAB?principle,use Cu₂ O particles with different morphologies as templates to fabricate Cu₂O@Zn?OH?2heterojunction.In this composite,the morphology of Cu₂ O is preserve completely,and form a lamellar structure compose of Zn?OH?2 sheets on the surface of Cu₂ O crystals.This material has stable structure and excellent photocatalytic performance for the degradation of organic dye,the lamellar structure of Zn?OH?2 enhances the absorption capacity of the composite to dye molecules,thus can accelerate the degradation rate of dye molecules by Cu₂ O.Comparing to the single Cu₂ O material,the catalytic efficiency of the composite improve a lot.