富炭硬沥青基WO3/TiO2催化剂提升染料和药物降解的光催化行为研究  

Insights into the photocatalytic behavior of carbon-rich shungite-based WO3/TiO2 catalysts for enhanced dye and pharmaceutical degradation

作　　者：Zeynep Balta Esra Bilgin Simsek 

机构地区：[1]Department of Chemical and Process Engineering,Faculty of Engineering,Yalova University,77100 Yalova,Turkey

出　　处：《新型炭材料》2020年第4期371-383,共13页New Carbon Materials

摘　　要：采用溶剂热法制备出富炭硬沥青基WO3/TiO2催化剂。通过光电子能谱议(XPS)、红外光谱仪(FTIR)、拉曼光谱仪(Raman)、扫描电镜(SEM)和UV-Vis漫反射光谱仪(DRS)等手段表征催化剂的形貌、结构、光学和物理性质。SEM观察到硬沥青表面完全被WO3/TiO2颗粒覆盖。Raman和XPS分析表明,富炭硬沥青与WO3,TiO2复合良好。DRS结果显示在带隙较低时(2.83 eV),富炭硬沥青基WO3/TiO2催化剂对可见光的吸收性能得到提高。在UV-A辐照下,通过降解橙色Ⅱ染料和药物来探讨所制催化剂的光催化性能。橙色Ⅱ染料降解度随着硬沥青添加比例增加而增加,这归因于吸附和光催化的协同效应,即光吸收的增加和光产生的空穴和电子在W/Ti界面容易转移。而且,为了对比硬沥青原料与所制催化剂的吸附性能,在不同pH值下进行了批量吸附实验,并采用等温线和动力吸附模型探讨了温度和吸附值。本研究提供了富炭硬沥青作为自然碳源应用于碳基光催化材料制备思路。Carbon-rich shungite-based WO3/TiO2 catalysts were synthesized by a solvothermal method. The morphological, structural, optical and physical features of the catalysts were characterized by XPS, FTIR, Raman spectroscopy, SEM and UV-Vis diffuse-reflectance spectroscopy(DRS). The photocatalytic performance of the catalysts was investigated for the degradation of Orange Ⅱ dye and pharmaceuticals under UV-A irradiation. SEM images show that the shungite surface is completely covered with WO3/TiO2 particles. Raman and XPS analyses demonstrate that the carbon-rich shungite is well-incorporated with the WO3 and TiO2. UV–Vis DRS indicates enhanced visible-light absorption and a lowered band gap(2.83 eV) for the catalysts. The degradation degree of Orange Ⅱ increases with increasing shungite ratio, which is ascribed to a combined effect of adsorption and photocatalysis, and the improved light absorption and easy transfer of photogenerated holes and electrons across the interface of W/Ti. Mechanism studies indicate that the π-π conjugation between a dye molecule and the aromatic bonds of carbon materials are more dominant rather than columbic interactions, and that ·O2- is the main species in Orange Ⅱ degradation. However, the Orange Ⅱ degradation efficiency is lowered in drinking water due to the photo-generated hole(h+)-scavenging effects by organic matter and salts and their competing adsorption with the target pollutant in the active sites on the catalyst surface. This work provides a possible use of the carbon-rich shungite as a natural carbon resource for the fabrication of carbon-based photocatalysts.

关 键 词：硬沥青 WO3 TIO2 光催化 橙色Ⅱ染料 药物 

分 类 号：TB33[一般工业技术—材料科学与工程]