还原氧化石墨烯修饰Bi_2WO_6提高其在可见光下的光催化性能(英文)

Reduced Graphene Oxide-Modified Bi_2WO_6 as an Improved Photocatalyst under Visible Light

通过两步水热法合成了一种新型的还原氧化石墨烯(RGO)修饰的Bi2WO6(Bi2WO6-RGO),结果表明其在可见光下的光催化性能得到了显著的提高.研究了RGO在Bi2WO6-RGO中的含量对其光催化性能的影响,从而确定出RGO相对于Bi2WO6的最佳掺杂质量比值为1%.通过扫描电镜(SEM)研究发现,RGO并没有改变Bi2WO6光催化剂的结构和形貌.Bi2WO6-RGO在可见光下的光催化性能得以提高可以归功于RGO.其可能的机理是石墨烯的存在有利于光生载流子(激子)的分离,从而导致产生更多的O2●-用于有机染料污染物(如罗丹明B(RhB))的降解.RhB分子在石墨烯上的有效吸附可能也是导致Bi2WO6-RGO光催化性能提高的另一原因.

A new and improved photocatalyst, reduced graphene oxide （RGO）-modified Bi2WO6 （Bi2WO6-RGO）, was synthesized by a two-step hydrothermal process. The effect of RGO content on photoactivity was investigated and the optimum mass ratio of RGO to Bi2WO6 was determined to be 1%. Based on scanning electron microscopic study, RGO does not change the structure and morphology of the Bi2WO6 photocatalyst. Therefore, the improvement in the photoactivity of the Bi2WO6-RGO composite is undoubtedly ascribed to RGO. The presence of graphene can facilitate the dissociation of photogenerated excitons, which leads to more O2●- to degrade dye pollutants like rhodamine-B （RhB）. Moreover, the efficient adsorption of RhB molecules on graphene is another reason for the improved photoactivity.