Fabrication And Photocatalytic Property Of Nano Cuprous Oxide

Cu₂O has advantage in its narrow bandgap?2.17 eV?,direct bandgap,and facile fabrication.However,Cu₂O has low photoelectric conversion efficiency for the photocatalytic application,due to its short carrier life time.To increase the photoelectric conversion efficiency of Cu₂O,two methods had been utilized:fabricating nanostructure Cu₂O to reduce the bulk carrier combination;forming interface electron field to facilitate the separation of electrons and holes by forming nano composing Cu₂O with metals and other semiconductors.Here,to achieve high photoelectric conversion efficiency of Cu₂O,the nanostructure and composition of the tree-like nanowire Cu₂O had been fabricated by hydrothermal method.It's photocatalytic activity had also been studied.The main content is divided into three parts:synthesis and characterization of the tree-like nanowire Cu₂O;photocatalytic activity of the tree-like nanowire Cu₂O by degrading methyl orange?MO?;extended investigation in synthesis and characterization of Ag-Cu₂O nanocomposite particles.The reaction temperature is in the range of 150-200? and the reaction time is 12h.When 80?L of O-anisidine was added,the nanowire Cu₂O surface had a uniformly distributed dendritic structure.With the increase in reaction temperature,Cu impurity appeared in Cu₂O nanowires.The morphology and phase analysis of the as-prepared samples were performed.Transmission electron microscopy?TEM?results showed that the growth direction of these branched structures and the nanowire trunks were perpendicular to each other.And the growth directions were[100]and[011],respectively.Nanowire polyhedral Cu₂O was prepared by adjusting the reaction temperature and the concentration of the reactants.Photocatalytic degradation of methyl orange?MO?without addition catalysis had been realized by tree-like nanowire Cu₂O.In the experiment,tree-like nanowires Cu₂O was prepared at 150-180?.Without any additional H₂O_2,high photocatalytic degradation rate of tree-like nanowire Cu₂O had been realized.Tree-like nanowires Cu₂O prepared at 150? has the highest photocatalytic degradation rate,90%degradation of MO in 20 min.For photoelectrochemical test,the nanowire Cu₂O has excellent photo-response,and the photocurrent density reaches 0.43?A cm^-2.The specific surface area of tree-like nanowire Cu₂O is around 20.35 m² g^-1.The growth temperature had small influence on the specific surface area of tree-like nanowire Cu₂O.Here,the high photocatalytic activity of nanowire Cu₂O prepared at 150? may be attributed to its high purity.Due to the existence of Cu dopants in the tree-like nanowire Cu₂O prepared at temperatures of 160-180?,deep-level doping results carrier recombination centers and low degradation efficiency.Photo-reduction and chemical reduction methods were used to deposit Ag nanoparticles?Ag NPs?on the surface of tree-like nanowire Cu₂O and nanowire polyhedron Cu₂O to form a nanocomposite structure.From the analysis of the structure,composite and surface morphology,Ag NPs can be deposited on the surface of Cu₂O,and the composition ration of Ag NPs can be tuned by changing the ratio of AgNO₃ to Cu₂O.The tree-like nanowire Cu₂O structure was successfully prepared by hydrothermal method,and further controlled by increasing the temperature to form nanowire polyhedral Cu₂O.In addition,Cu impurities in tree-like nanowire Cu₂O can also be controlled by controlling the temperature.The tree-like nanowire Cu₂O can achieve high degradation of MO without H₂O₂.This work provides a new preparation method for the preparation of nano-Cu₂O materials with high catalytic activity.