石墨烯负载TiO2复合材料的制备及光催化降解印染废水的研究

利用溶胶-凝胶法和水热法制备了石墨烯改性TiO2催化剂。通过X射线衍射仪(XRD)、紫外-可见分光光度计(UVVis)、扫描电镜(SEM)、光致发光荧光光谱仪(PL)对催化剂进行表征,并考察了该催化剂对亚甲基蓝的光催化降解性能。结果表明,石墨烯成功负载到TiO2表面,不同石墨烯负载量的TiO2均为锐钛矿结构,石墨烯的加入减小了TiO2的禁带宽度,增大了光吸收范围,延长了光生载流子寿命。催化剂活性随石墨烯负载量的增加先增大后减小,3%石墨烯负载量的TiO2具有最高的光催化活性,达到85.5%。光催化活性的提升原因:(1)光吸收的增加;(2)石墨烯的加入促进了电子的转移,延长了光生载流子的寿命。

Preparation of graphene-loaded TiO2 composite and photocatalytic degradation of printing and dyeing wastewater

Graphene loaded TiO2 catalysts were successfully prepared by sol-gel and hydrothermal method.The products were characterized by XRD,UV-Vis,SEM and PL.The photocatalytic degradation of methylene blue (MB) were investigated.The results indicated that graphene was successfully loaded into TiO2,and the TiO2 with different graphene loading content were of anatase structure.The addition of graphene reduced the band gap of TiO2,enlarged the optical absorption range and the lifetime of photogenerated carriers.With the increase of graphene loading content,the activity of catalyst firstly increased and then decreased.3% graphene loaded TiO2 had the highest photocatalytic activity,reaching 85.5%.The enhancement of photocatalytic activity was due to:(1) the increase of light absorption;(2) the addition of graphene promoted electron transfer and enlarged the lifetime of photogenerated carriers.