New Technology For Preparation Of Graphite Phase Nitrogen Carbon Nonmetallic Photocatalyst

We are facing two serious problems:environmental pollution and energy shortage.The main solution to alleviate the crisis is to use suitable semiconductor photocatalyst to make rational use of sunlight.However,most of the traditional photocatalysts are precious metal catalysts such as titanium dioxide,which are expensive and difficult to obtain.g-C₃N₄ is mainly composed of two elements,C and N,which are abundant in the earth,cheap and easy to obtain.Therefore,g-C₃N₄ has been applied in the production of H₂ by photolysis of water,degradation of pollutants and so on.However,the band gap of g-C₃N₄ is 2.7 eV,and the corresponding spectral response range is within 475 nm.The utilization of light is low,only part of visible light can be used,and ultraviolet and infrared can not be used at all.At the same time,the utilization of light by photogenerated electrons and holes is difficult to achieve a satisfactory level.In order to improve the photocatalytic efficiency of g-C₃N₄,sulfate-modified and in situ S-doped g-C₃N₄ were synthesized by acid hydrothermal treatment and DBD plasma treatment on the basis of g-C₃N₄ to improve the photoquantum efficiency and reduce the electron-hole recombination rate.Sulfate-modified graphitic carbon nitride nanorods as efficient photocatalyst for H₂O₂ production was prepared via acid-hydrothermal method.XRD,N₂ adsorption,UV-Vis,FT-IR,SEM,XPS,TPD,EIS,and PL were used to characterize the obtained catalysts.Sulfate modification not only influences the morphology,structure property and optical property,but also promotes the O₂ adsorption ability,leading to the improved separation rate of electrons-holes.Sulfate modified g-C₃N₄ catalyst shows the H₂O₂concentration of 2.7 mmol·L^-1,more than 2.7 time higher than that of neat g-C₃N₄.This work provides a new method for the modification of g-C₃N₄based catalyst.Dielectric barrier discharge?DBD?plasma is considered to be a promising method to synthesize and modify solid catalyst.DBD plasma was used to synthesize S-doped g-C₃N₄ catalyst in situ under H₂S atmosphere for the first time.XRD,N₂ adsorption,UV-Vis,SEM,XPS,EIS,and PL were used to characterize the obtained catalysts.The photocatalytic RhB degradation of as-prepared catalyst was investigated.The results show that,compared with traditional roasting method,H₂S plasma treatment can dope more sulfur into g-C₃N₄ lattice.Such high sulfur content has a significant impact on the morphology,optical property,and electronic structure of the catalyst.The sulfur doped g-C₃N₄ prepared by plasma treatment displays much higher RhB degradation rate than that prepared by traditional roasting method.This work provides a new strategy for synthesizing heteroatoms doped g-C₃N₄ based catalyst.