Li Haitao, Li Na, Wang Ming, Zhao Beiping, Long Fei
College of Material Science and Engineering, Guilin University of Technology, Guilin 541004, People's Republic of China.
Guangxi Ministry-Province Jointly-Constructed Cultivation Base for State Key Laboratory of Processing for Nonferrous Metal and Featured Materials, Guilin University of Technology, Guilin 541004, People's Republic of China.
R Soc Open Sci. 2018 Mar 28;5(3):171419. doi: 10.1098/rsos.171419. eCollection 2018 Mar.
Graphitic carbon nitride (g-CN) nanosheets with a thickness of only a few nanometres were obtained by a facile deammoniation treatment of bulk g-CN and were further hybridized with BiWO nanoparticles on the surface via a solvothermal method. The composite photocatalysts were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflection spectroscopy and X-ray photoelectron spectroscopy (XPS). The HR-TEM results show that the nano-sized BiWO particles were finely distributed on g-CN sheet surface, which forms heterojunction structure. The UV-vis diffuse reflectance spectra (DRS) show that the absorption edge of composite photocatalysts shifts towards lower energy region in comparison with those of pure g-CN and BiWO. The degradation of methyl orange (MO) tests reveals that the optimum activity of 8 : 2 g-CN-BiWO photocatalyst is almost 2.7 and 8.5 times higher than those of individual g-CN and BiWO. Moreover, the recycle experiments depict high stability of the composite photocatalysts. Through the study of the influencing factors, a possible photocatalytic mechanism is proposed. The enhancement in both photocatalytic performance and stability was caused by the synergistic effect, including the effective separation of the photogenerated electron-hole pairs at the interface of g-CN and BiWO, the smaller the particle size and the relatively larger specific surface area of the composite photocatalyst.
通过对块状石墨相氮化碳（g-CN）进行简便的脱氨处理，获得了厚度仅为几纳米的g-CN纳米片，并通过溶剂热法将其与表面的BiWO纳米颗粒进一步杂化。采用粉末X射线衍射、扫描电子显微镜、透射电子显微镜、紫外-可见漫反射光谱和X射线光电子能谱（XPS）对复合光催化剂进行了表征。高分辨透射电子显微镜（HR-TEM）结果表明，纳米尺寸的BiWO颗粒均匀分布在g-CN片层表面，形成了异质结结构。紫外-可见漫反射光谱（DRS）表明，与纯g-CN和BiWO相比，复合光催化剂的吸收边向低能量区域移动。甲基橙（MO）降解测试表明，8 : 2的g-CN-BiWO光催化剂的最佳活性分别比单独的g-CN和BiWO高出近2.7倍和8.5倍。此外，循环实验表明复合光催化剂具有高稳定性。通过对影响因素的研究，提出了一种可能的光催化机理。光催化性能和稳定性的提高是由协同效应引起的，包括g-CN和BiWO界面处光生电子-空穴对的有效分离、复合光催化剂较小的粒径和相对较大的比表面积。
