The Preparation Of Carbon Nitride/metal Oxide Composite Material And Its Photocatalytic Antibacterial Performance

Graphite carbon nitride?g-C₃N₄?is a non-metallic semiconductor and composed of C and N elements,because of its visible light response,good stability,controllable structure and good photocatalytic performance,it became the research focus in the field of photocatalysis.Metal-oxide semiconductor was combined with g-C₃N₄ to form the heterostructure that can improve photocatalytic performance.In this paper,g-C₃N₄ was prepared directly by calcining method,In₂O₃/g-C₃N₄,CeO₂/g-C₃N₄ and WO₃/g-C₃N₄ composites were synthesized by blending calcination method.XRD,FT-IR,SEM,DRS,PT and bacterial inactivation experiment were used to study the structure,morphology,photoelectric property and photocatalytic antibacterial activity of materials,and the mechanism of photocatalytic antibacterial activity was described by scavenger experiment.The main contents are as follows:?1?g-C₃N₄ was prepared by calcining method,In₂O₃/g-C₃N₄ composites were prepared by blending calcination method.The results of XRD and FT-IR showed that the composites were prepared successfully.The SEM showed that In₂O₃ was distributed on the g-C₃N₄ surface or coated in g-C₃N₄ evenly.The PT results indicated that the photocurrent intensity of 27.2%In₂O₃/g-C₃N₄ was 3 and 12 times higher than g-C₃N₄ and In₂O₃,respectively.The antibacterial results showed that 27.2%In₂O₃/g-C₃N₄ had the best antibacterial effect,and the antibacterial rate against E.coli and S.aureus were 99.85%and 99.81%,respectively,when it was irradiated 60 min under LED lamp,which was superior to g-C₃N₄ and In₂O₃.The active species detection results showed that the main active species of In₂O₃/g-C₃N₄ composite were e^-,H₂O₂,h⁺and·O₂^-,and the photocatalytic antibacterial mechanism followed the Z-scheme heterojunction.?2?g-C₃N₄ was prepared by calcining method,CeO₂ was prepared by thermal decomposition method,CeO₂/g-C₃N₄ composites were prepared by blending calcination method.The results of XRD and FT-IR showed that the composites were prepared successfully.The SEM showed that CeO₂ was distributed on the g-C₃N₄surface or coated in g-C₃N₄ evenly.The PT results indicated that the photocurrent intensity of 19.5%Ce O₂/g-C₃N₄ was 4 and 5 times higher than g-C₃N₄ and CeO₂,respectively.The antibacterial results showed that 19.5%CeO₂/g-C₃N₄ had the best antibacterial effect,and the antibacterial rate against E.coli and S.aureus were both100%,when it was irradiated 60 min under LED lamp,which was superior to g-C₃N₄and CeO₂.The active species detection results showed that the main active species of CeO₂/g-C₃N₄ composite were e^-,H₂O₂,h⁺and·O₂^-,·OH was active speciese but less useful,and the photocatalytic antibacterial mechanism followed the Z-scheme heterojunction.?3?g-C₃N₄ was prepared by calcining method,WO₃/g-C₃N₄ composites was prepared by blending calcination method.The results of XRD and FT-IR showed that the composites were prepared successfully.The SEM showed that WO₃ was distributed on the g-C₃N₄ surface or coated in g-C₃N₄ evenly.The PT results indicated that the photocurrent intensity of 15.7%WO₃/g-C₃N₄ was 4 and 9 times higher than g-C₃N₄ and WO₃,respectively.The antibacterial results showed that 15.7%WO₃/g-C₃N₄ had the best antibacterial effect,and the antibacterial rate against E.coli and S.aureus were both 100%,when it was irradiated 45 min under LED lamp,which was superior to g-C₃N₄ and WO₃.The active species detection results showed that the main active species of WO₃/g-C₃N₄ composite were e^-,H₂O₂,·O₂^-and h⁺,·OH was active speciese but less useful,and the photocatalytic antibacterial mechanism followed the Z-scheme heterojunction.?4?Comparing the antibacterial rate against E.coli of the best sample of three composites which are 27.2%In₂O₃/g-C₃N₄,19.5%CeO₂/g-C₃N₄ and 15.7%WO₃/g-C₃N₄,and the result showed that 15.7%WO₃/g-C₃N₄>19.5%CeO₂/g-C₃N₄>27.2%In₂O₃/g-C₃N₄.15.7%WO₃/g-C₃N₄ had the best antibacterial effect and the less combined amount of metal-oxide semiconductor.