Zhan Sihui, Hou Qianlei, Li Yi, Ma Shuanglong, Wang Pengfei, Li Yanan, Wang Haitao
Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University Tianjin 300071 P. R. China
Department of Chemistry, Tianjin University Tianjin 300072 P. R. China.
RSC Adv. 2018 Oct 8;8(60):34428-34436. doi: 10.1039/c8ra06923a. eCollection 2018 Oct 4.
Visible-light-driven photocatalytic disinfection is highly desired for water treatment due to its advantages such as wide applicability and being free of disinfection byproducts. In this study, AgBr/g-CN hybrid nanocomposites were evaluated as photocatalysts under visible light irradiation for water disinfection using as a model pathogen. The physicochemical and photo-electrochemical properties of the photocatalyst were systematically characterized using advanced techniques including scanning electron microscopy (SEM), transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), UV-visible diffuse reflectance spectra (DRS), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectra and electron spin resonance (ESR) spectroscopy. The inactivation mechanism of was systematically investigated by monitoring the morphology change of the bacteria and analyzing the role of reactive species. The optimized AgBr/g-CN hybrid photocatalyst exhibited remarkably enhanced visible-light-driven photocatalytic disinfection performance towards over that of pure g-CN and AgBr under visible light, which could completely inactivate 10 cfu mL in 90 min. Quenching studies indicated that h is the main reactive species responsible for inactivating . The mechanism study revealed a Z-scheme charge transfer mechanism between AgBr and g-CN. The g-CN could effectively trap the photogenerated conduction band electrons of AgBr a Z-scheme type of route, thus significantly promoting the electron-hole separation. The trapping of electrons by g-CN could facilitate h accumulation, which accounts for the better disinfection performance of AgBr/g-CN compared to AgBr and g-CN.
可见光驱动的光催化消毒由于其适用性广和无消毒副产物等优点，在水处理中备受青睐。在本研究中，评估了AgBr/g-CN杂化纳米复合材料作为光催化剂在可见光照射下对作为模式病原体的水进行消毒的性能。使用包括扫描电子显微镜（SEM）、透射电子显微镜（高分辨率透射电子显微镜，HRTEM）、粉末X射线衍射（XRD）、紫外可见漫反射光谱（DRS）、X射线光电子能谱（XPS）、光致发光（PL）光谱和电子自旋共振（ESR）光谱等先进技术，系统地表征了光催化剂的物理化学和光电化学性质。通过监测细菌的形态变化并分析活性物种的作用，系统地研究了的灭活机制。优化后的AgBr/g-CN杂化光催化剂在可见光下对的可见光驱动光催化消毒性能比纯g-CN和AgBr有显著增强，在90分钟内可完全灭活10 cfu mL 。猝灭研究表明，h是负责灭活的主要活性物种。机理研究揭示了AgBr和g-CN之间的Z型电荷转移机制。g-CN可以通过Z型途径有效地捕获AgBr的光生导带电子，从而显著促进电子-空穴分离。g-CN对电子的捕获可以促进h的积累，这解释了AgBr/g-CN比AgBr和g-CN具有更好消毒性能的原因。
