Preparation And Photocatalytic Performance Of Heteroatom-doped Carbon-coated Cerium-based,titanium-based And Semiconductors And Heterostructures

Energy crisis and environmental pollution are the two major problems facing mankind.Semiconductor photocatalysis can convert solar energy into chemical energy and is an effective way to solve the above problems.However,the currently synthesized semiconductor photocatalysts have problems such as few active sites,small spectral absorption range,and low separation efficiency of electrons and holes,which seriously affect their practical applications.This thesis mainly uses metal organic framework（MOF）as the precursor to prepare heteroatom-doped carbon-coated porous metal oxide composites through high-temperature calcination.The goal is to increase its surface active sites by constructing a porous structure.The construction of a multi-metal heterostructure increases the spectral absorption range and the coating of heteroatom-doped carbon realizes the effective separation of electrons and holes.The main contents are as follows:1.In the solvothermal reaction process,a regulator containing N,S is introduced to synthesize Ce-MOF-808 precursor,and a three-dimensional porous hinge-like structure assembled from two-dimensional nanosheets is obtained by high-temperature calcination.N,S-doped C Coated cerium oxide（Ce O2@N,S-C HN）.The photoelectric performance of Ce O2@N,S-C HN and the photolysis of water hydrogen production performance were tested.It was found that due to the synergistic effect of N,S-doped C coating and porous structure,the electron and hole separation efficiency of the material was enhanced.Improve the photocatalytic activity of the material.2.Add Cd²⁺and S^2-to the Ce O2@N,S-C HN catalyst synthesized in system 1,and then generate N,S-C/Ce O2@Cd S with a hinge-like porous structure through further solvothermal reaction.The photoelectric performance of N,S-C/Ce O2@Cd S and the performance of photolysis of water to produce hydrogen and benzaldehyde were tested.It was found that due to the effect of heterojunction,the separation efficiency of electrons and holes and the absorption efficiency of visible light were further enhanced,which greatly improved The photocatalytic activity of the material.3.The monodisperse NH2-MIL-125（Ti）precursor with cubic structure is generated through simple solvothermal reaction,and N-C/TiO2 is obtained after annealing in Ar atmosphere,and N-doped C is generated through secondary solvothermal reaction Coated titanium dioxide and cadmium sulfide heterostructure（N-C/TiO2@Cd S）.The photocatalysis and photoelectric performance test showed that the presence of the nitrogen-doped carbon layer increased the electrical conductivity of the material,increased the electron transport rate of the heterojunction,and improved the catalytic performance of the material.