Preparation And Visible Light Catalytic Properties Of Semiconductor Composite Materials Based On G-C₃N₄

Nowadays,semiconductor photocatalysis technology has become a hot water treatment technology.g-C₃N₄ is considered a promising candidate material due to its advantages of simple preparation,low cost,environmental friendliness,a moderate band gap,and high thermal stability.However,the shortcomings of photogenic e^-/h⁺recombination and photoresponsive edge width restrict its application,so it is necessary to modify g-C₃N₄ to a certain extent to improve its photocatalytic performance.In this paper,a new method combining hydrothermal synthesis and wet impregnation has been used to synthesize the ternary photocatalysts MoS₂-Zr O₂/g-C₃N₄ and MoS₂-V₂O₅/g-C₃N₄.The crystallinity and morphology of the catalysts were characterized by X-ray diffraction（XRD）and field emission scanning electron microscopy（FE-SEM）.Fourier Transform infrared spectroscopy（FT-IR）is used to analyze chemical bond types in catalysts.The band gap and elemental composition of the catalysts were measured by UV-Vis diffuse reflectance spectroscopy（UV-Vis DRS）,X-ray photoelectron spectroscopy（XPS）,and energy dispersive analysis（EDS）.The characterization showed that the catalyst was successfully prepared and the band gap was improved.The photocatalytic activity of the photocatalyst was studied by degrading Rhodamine B solution with a certain concentration under the condition of simulating visible light.In addition,the stability and photocatalytic mechanism of the ternary composite photocatalyst were investigated by cyclic and active free radical trapping experiments.The photocatalyst MoS₂-Zr O₂/g-C₃N₄ was synthesized by a new method of hydrothermal synthesis and wet impregnation.In the simulation of visible light,a ternary photocatalyst MoS₂-V₂O₅/g-C₃N₄ was used to degrade Rhodamine B solution at a certain concentration.The experimental results show that the photocatalytic performance of pure g-C₃N₄ is much lower than that of the MoS₂-Zr O₂/g-C₃N₄ ternary photocatalyst.After 40 min of illumination,the degradation rate of 5%MoS₂-Zr O₂/g-C₃N₄ reached 99.8%.The results of UV-Vis diffuse reflectance spectroscopy（UV-Vis DRS）and photoluminescence spectroscopy（PL）also show that doping MoS₂ and Zr O₂into g-C₃N₄ can effectively reduce the band gap and accelerate the separation rate of photogenerated e^-/h⁺pairs.In addition,after five cycles of experiments,it was found that the degradation rate of MoS₂-Zr O₂/g-C₃N₄ terpolymer photocatalyst for Rhodamine B solution can still remain above 90%,showing good stability.The photocatalyst MoS₂-V₂O₅/g-C₃N₄ was synthesized by a new method of hydrothermal synthesis and wet impregnation.In the simulation of visible light,a ternary photocatalyst MoS₂-V₂O₅/g-C₃N₄ was used to degrade Rhodamine B solution at a certain concentration.The experimental results show that the photocatalytic performance of pure g-C₃N₄ is much lower than that of the MoS₂-Zr O₂/g-C₃N₄ ternary photocatalyst.After 30 min of illumination,the degradation rate of 5%MoS₂-Zr O₂/g-C₃N₄ reached 99.18%.In addition,the test results of UV-Vis diffuse reflectance spectroscopy（UV-VIS DRS）also show that doping MoS₂ and V₂O₅ into g-C₃N₄ can effectively reduce the band gap.In addition,the possible photocatalytic mechanism of the MoS₂-V₂O₅/g-C₃N₄ ternary composite photocatalyst was deduced through the trapping experiment of active free radicals.In addition,the possible photocatalytic mechanism of the MoS₂-V₂O₅/g-C₃N₄ ternary composite photocatalyst was deduced through the trapping experiment of active free radicals.g-C₃N₄ was modified by doping MoS₂,V₂O₅ and Zr O₂ into g-C₃N₄.The test results show that doping can not only effectively reduce the band gap,but also accelerate the separation rate of photogenerated e^-/h⁺pairs so as to improve the photocatalytic performance.It also provides new ideas for the modification of g-C₃N₄ and the preparation of new photocatalysts in the future.