石墨相氮化碳-碘氧化铋层状异质结的构建及其光催化杀菌性能

Construction of Graphitic Carbon Nitride-Bismuth Oxyiodide Layered Heterostructures and Their Photocatalytic Antibacterial Performance

以脲素作为前驱物,采用热聚合法制备薄层石墨相氮化碳(g-C_3N_4),然后在其表面原位合成层状碘氧化铋,构筑石墨相氮化碳-碘氧化铋层状异质结(g-C_3N_4/BiOI).合成样品的形貌、比表面积、晶体结构、分子结构、光吸收性能及其表面特性分别采用透射电镜、BET氮吸附、X射线粉末衍射、红外光谱仪、紫外可见漫反射和X射线光电子能谱分析进行表征,并考察合成的催化剂在可见光照射下光催化杀菌性能,研究中通过牺牲剂捕获的方法进一步揭示合成的g-C_3N_4/BiOI在杀菌过程中的机制.结果表明,合成的样品具有层状异质结结构,其比表面积为63 m^2·g^(-1),合成样品光吸收边可以达到600 nm.光催化活性测试表明g-C_3N_4/BiOI能够在4 h内将细菌杀死,其杀菌效果明显高于纯的g-C_3N_4和BiOI,其在光催化灭菌过程中主要的活性物种是光生空穴.

The thin layered graphitic carbon nitride（ g-C3N4） was prepared by the thermal polymerization process with urea as the precursor. The layered heterostructure of graphitic carbon nitride-bismuth oxyiodide（ g-C3N4/BiOI） was constructed by the in-situ synthetization of bismuth oxyiodide（ BiOI） on the surface of the thin layered g-C3N4. The morphology,specific surface area,crystal structure,molecular structure,light absorption properties,and surface properties were characterized by TEM,BET,XRD,FT-IR,UV-Vis DRS,and XPS,respectively. The disinfection performance of the synthesized catalysts under visible light irradiation was investigated. The antibacterial mechanism of g-C3N4/BiOI in the photocatalytic process was further revealed by the capture of sacrificial agents. The results indicate that the prepared sample has a layered heterojunction structure with a specific surface area of 63 m^2·g^-1and its light absorption side can obtain 600 nm. The results of the photocatalytic activity test indicate that g-C3N4/BiOI can kill bacteria within 4 h,which is significantly higher than that of g-C3N4 and BiOI. The main active species of g-C3N4/BiOI in the photocatalytic process can be attributed to the photogenerated holes.