Study On Graphite Carbon Nitride Co-Doped With Multi-Metal And Sulfur And Its Photo-/Thermal-Catalytic Performance

With the prominent problems of environmental pollution and energy crisis,people need a new type of clean energy conversion method.At the same time,Semiconductor photocatalysis,as a new type of catalytic technology,can utilize clean energy solar energy to achieve efficient energy conversion and reduce pollutant degradation,such as water splitting,hydrogen production,CO₂reduction,organic synthesis and other fields.As a new type of polymer semiconductor photocatalyst,graphitic carbon nitride(g-C₃N₄)has the advantages of large specific surface area,low price,good stability and so on.However,graphitic carbon nitride also has weakness such as low catalytic activity.As a new direction of heterogeneous catalysts,Single-atom catalysts（SACs）have the advantages of high atom utilization,high atomic activity,and are favored by scientific researchers.However,single-atom catalysts cannot utilize synergistic effects and have relatively narrow applicability.On this basis,the Dual atomic catalyst（DACs）can utilize the synergistic effect between atoms to produce the effect of"1+1>2".In this paper,the modified graphitic nitride co-doped with dual metal Ag-Fe or Ag-Cu along with non-metal S was prepared respectively by serial strategy of pyrolysis,wet chemical reduction and annealing,using potassium chromate and metal nitrate as precursors.The structure and physicochemical properties of the materials were studied by Transmission electron microscope（TEM）,X-ray diffraction（XRD）,Ultraviolet-visible photometer（UV-vis）,electrochemical workstation and other instruments.A series of organic synthesis reaction was investigated,such as the oxidation of phenylsilane,phenylboronic acid,α-terpinene,anisole sulfide,benzene,as well as coupling of styrene andammoniumthiocyanate,selectivedehydrogenationof1-methyl-1,2,3,4-tetrahydroisoquinoline.The results show that Fe or Cu doping plays a major role in reducing the band gap of carbon nitride materials and improving its light absorption properties,while synergistic effects between Ag and Fe or Cu could improve the activity in photocatalysis and thermalcatalysis.