Construction And Visible Light Photocatalytic Property Of ZnFe₂O₄/ZnO Heterojunction

ZnO is one of the excellent photocatalysts as possessing high electron mobility and faster photoproduction electronic transmission. But it can only absorb ultraviolet light because of its wider band gap. Zn Fe2O4 is a narrow band gap semiconductor with strong ability to absorb visible light. But its photocatalytic activity is low due to the easily recombination of photogenerate electron and hole. In this paper heterojunction Zn Fe2O4/Zn O and Zn Fe2O4/Zn O/Ag have been constructed in order to obtain novel nanomaterials with enhanced photocatalytic activity under visible light. The main contents are listed below:1. Zn Fe2O4 nanoparticles and Zn Fe2O4/Zn O heterojunction were prepared by chemical coprecipitation method and hydrothermal method, respectively. Ag nanoparticles were doped on the surface of Zn Fe2O4/Zn O heterostructure by using a silver mirror reaction.2. The crystal structure, morphology, band gap, optical and electrochemical properties of the system were characterized by XRD, XPS, TEM, EDS, DRS, CV and LSV analysises.3. The optimum synthetic conditions of Zn Fe2O4/Zn O and Zn Fe2O4/Zn O/Ag heterojunction have been determined via comparing the photocatalytic degradation efficienty of methyl orange under 85 W visible light irradiation. The effects of initial concentration of methyl orange, p H, initial concentration of catalyst, amount of Zn O, amount of Ag doping, hydrothermal temperature, hydrothermal time and calcination temperature etc on the degradation of methyl orange solution have been investigated.4. The possible photocatalytic mechanisms of Zn Fe2O4/Zn O and Zn Fe2O4/Zn O/Ag heterojunction have been proposed. The function of Ag nanoparticles in Zn Fe2O4/Zn O/Ag heterojunction has been discussed. We also evaluated the stability and magnetism of heterojunction photocatalysts.