Design Of Two Dimensional Nanomaterial-based Photocatalyst And Photocatalytic Performance Research

The photocatalytic technology used to solve the increasingly serious environmental pollution and energy shortage problems is being studied more and more.In view of the unique characteristics of two-dimensional materials including high specific surface area,shorter electron/hole migration paths and abundant active sites,this paper uses partially phosphated two-dimensional MoS₂(P-MoS₂)and Bi OBr as the matrix to compound CdS and Bi₂O₂CO₃(BOC),respectively.And P-MoS₂/CdS and BOC/Bi OBr composite photocatalyst were prepared.In addition,the benzene and K⁺co-doped g-C₃N₄was prepared by a precursor-engineering coupled molten-salt strategy.The structure,composition,and photoelectrochemical performance of the composite photocatalyst were characterized,and its photocatalytic performance was investigated.The specific research contents are as follows:(1)The P-MoS₂/CdS composite photocatalyst was prepared by compounding CdS with a partially phosphated MoS₂matrix.The influence of the phosphating temperature and time of MoS₂and the mass ratio of P-MoS₂on the hydrogen production rate of the catalyst was discussed.The experimental results show that,compared with MoS₂,the conduction band potential of P-MoS₂is more positive,which improves the conductivity of the catalyst and leads to more efficient electron-hole separation.The enlarged interplanar spacing on P-MoS₂allows more active sites to be exposed.The hydrogen production rate of 0.2P-MoS₂/CdS composite material is as high as 58.9(?)mol·h^-1,which is 2.9 times that of pure CdS and 2.3 times that of 0.2MoS₂/CdS,respectively.(2)The flower-like BOC/Bi OBr Z-type heterojunction was fabricated on bismuth oxycarbonate(BOC)by in-situ self-growth method.The effect of bismuth oxybromide(Bi OBr)content on the degradation of tetracycline and ciprofloxacin was investigated.BOC/Bi OBr-2 showed the highest degradation rates of tetracycline and ciprofloxacin within 120 minutes of 94.8%and 88.9%,respectively.This was attributed to the close contact between BOC and Bi OBr and the Z-Scheme electron transfer path of BOC/Bi OBr and generated oxygen vacancies.(3)The benzene and K⁺co-doped g-C₃N₄was prepared by a precursor-engineering coupled molten-salt strategy.The performance and mechanism of benzene and K⁺doping amount and their synergistic effect on improving the photocatalytic oxygen reduction of g-C₃N₄to produce H₂O₂were investigated.Molten salt calcination can improve the crystallinity and enhance light absorption of g-C₃N₄.Doped K⁺facilitates O₂adsorption and release of protons.Benzene doping can change the electronic structure of g-C₃N₄,and synergistically improves the electron-hole separation efficiency with K⁺.The KBCN produced 1402.2?M of H₂O₂in a 5%ethanol solution,which was 103 times higher than the original g-C₃N₄,and produced57.6?M of H₂O₂in pure water saturated with O₂.