National Center for Nanoscience and Technology, Beijing 100190, P.R. China.
Nanoscale. 2013 Nov 21;5(22):11291-7. doi: 10.1039/c3nr03969b. Epub 2013 Oct 4.
A novel ZnO/reduced graphene oxide (RGO)/CdS heterostructure was successfully synthesized via a facile three-step solution method. RGO serves as an interlayer between ZnO nanowires and CdS quantum dots (QDs), which provides a high speed charge transfer channel, leading to an enhanced charge separation efficiency. Under UV light irradiation, the photocatalytic activity of the ZnO/RGO/CdS heterostructure is 4.0 times and 1.9 times as high as those of pure ZnO and ZnO/RGO, respectively. Under visible light irradiation, the ZnO/RGO/CdS heterostructure shows a dramatic visible light photocatalytic activity which is 2.3 times higher than that of the ZnO/CdS photocatalyst. The photocurrent of the ZnO/RGO/CdS heterostructure under UV light irradiation was greatly enhanced and a photocurrent under visible light irradiation was observed. The enhanced photocatalytic activity and the extended light adsorption spectrum originate from the type-II ZnO/CdS band alignment and the introduction of RGO as a charge mediator. Our results might open up a promising way to develop novel and highly efficient RGO-based heterostructure photocatalysts.
一种新型 ZnO/还原氧化石墨烯（RGO）/CdS 异质结构通过简便的三步溶液法成功合成。RGO 作为 ZnO 纳米线和 CdS 量子点（QDs）之间的夹层，提供了高速电荷转移通道，从而提高了电荷分离效率。在紫外光照射下，ZnO/RGO/CdS 异质结构的光催化活性分别是纯 ZnO 和 ZnO/RGO 的 4.0 倍和 1.9 倍。在可见光照射下，ZnO/RGO/CdS 异质结构表现出显著的可见光光催化活性，比 ZnO/CdS 光催化剂高 2.3 倍。紫外光照射下 ZnO/RGO/CdS 异质结构的光电流大大增强，并观察到可见光照射下的光电流。增强的光催化活性和扩展的光吸收光谱源于 ZnO/CdS 能带排列的 II 型和 RGO 作为电荷中介的引入。我们的结果可能为开发新型高效的基于 RGO 的异质结构光催化剂开辟了一条有前景的途径。
