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

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.

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

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 m²·g^-1 and 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.