Preparation Of Nanometer Copper Bismuthate And Its Catalytic Performance

Copper bismuthate（CuBi₂O₄）with a spinel structure is a semiconductor material with a variety of physical and chemical properties.Because of its lower valence band structure,it has been widely studied in the field of photoelectrochemistry in recent years.In this paper,a one-step solvothermal method was used to modify copper bismuthate,and the rare earth lanthanum-doped copper bismuthate（La-CuBi₂O₄）and（CuO/CuBi₂O₄）composite catalysts were prepared.The effect of modification on the morphology,crystal phase and catalytic reduction properties of the catalyst was studied;and the effect of modification on the catalyst in the entire catalytic process was discussed and analyzed.The main research contents of this paper are as follows:1.A new type of La-doped La-CuBi₂O₄catalyst was prepared by the one-step hydrothermal solvent method.All the prepared catalysts were characterized by high-resolution transmission electron microscopy（HRTEM）,powder X-ray diffraction（XRD）,X-ray photoelectron spectroscopy（XPS）,hydrogen temperature programmed desorption（H₂-TPD）and electrochemical impedance spectroscopy（EIS）conducted characterization and performance studies.This rare earth lanthanum-doped catalyst is used as a catalyst for the reduction of 4-NP and toxic organic dyes,and its catalytic activity is significantly higher than that of pure phase CuBi₂O₄.Through the analysis of experimental data,we believe that La doping can improve the electron transport and H₂adsorption capacity of the catalyst surface.In the catalytic reduction process,the doped La³⁺and surface adsorbed hydrogen play a key role in the reduction reaction.La³⁺is reduced to La²⁺by trapping electrons to realize electron transfer,and the degradation of 4-NP is realized under the action of electrons and adsorbed H.2.Using a mixed solution of deionized water and ethanol as a solvent,a one-step solvothermal method was used to synthesize pure phase CuBi₂O₄and CuO/CuBi₂O₄catalysts,respectively.The catalytic activity of this type of composite catalyst is much higher than that of pure CuBi₂O₄,and when the molar ratio of Cu to Bi is（2:3.16）,the catalytic reduction of 4-NP using the prepared CuO/CuBi₂O₄catalyst has the highest efficiency,It reaches 96.17%,which is more than 3 times that of pure phase CuBi₂O₄.The improvement of the performance of CuO/CuBi₂O₄composite catalyst is mainly due to CuO can be regarded as an effective electron acceptor,which can accelerate the separation of CuBi₂O₄electrons and holes,thereby improving the reduction performance.