BiVOPreparation And Photocatalytic Properties Of 4 -ZnO Nanocomposites

While the development of industrialization makes our life more convenient,it brings us the problem of environmental pollution.We can use the photocatalytic properties of semiconductors to degrade contaminants.As a novel photocatalytic material,Bi VO₄ has the characteristic of visible light response.Though it has a high application prospect at present,but the electron-hole pair of traditional photocatalytic materials is easy to recombine,which limits the catalytic efficiency.Therefore,the synthesis and properties of BiVO₄ were studied,and the combination of BiVO₄-ZnO was explored to improve the photocatalytic efficiency.Using Bi?NO₃?₃·5H₂O,NH₄VO₃ and EG as materials,the self-assembled BiVO₄ of nano-sized particles was synthesized by hydrothermal method.The effects of annealing temperature,hydrothermal reaction time and hydrothermal temperature on the crystal form and morphology of the samples were investigated.Characterization was performed using XRD,SEM,EDS,TEM,UV-Vis,and UV-Vis DRS.Experiments have shown that:when heated at 150°C for 18 hours and after annealing at 450°C,BiVO₄ has the highest photocatalytic efficiency with a particle size of approximately 23.51nm and a band gap of approximately 2.45eV.Combining ZnO with BiVO₄ to improve the internal electron and hole recombination problems can improve the visible light response range and photocatalytic efficiency.A composite sample was prepared using Bi VO₄,Zn?CH₃COO?₂ and Na OH,with ZnO additions of 1%,3%,5%,7%and 10%.Experiments have shown that the crystal shape of the composite sample has not changed,and the surface roughness,specific surface area and crystallinity of 5%-ZnO are the highest.ZnO is deposited on the crystal surface of Bi VO₄?200?,forming a heterojunction.The forbidden band width of the composite sample was about 2.32eV,the particle size was 21.40nm,the degradation rate to RhB was 97%,and the catalytic efficiency of the composite sample was 2 times higher than that of BiVO₄.Compared with P25-TiO₂,both BiVO₄ and BiVO₄-ZnO have practical application capabilities.