State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University , Hangzhou 310027, People's Republic of China.
ACS Appl Mater Interfaces. 2014 Aug 13;6(15):12698-706. doi: 10.1021/am502700p. Epub 2014 Jul 16.
It is commonly considered that the morphology and interface of semiconductor-reduced graphene oxide (rGO) composite photocatalysts play a crucial role in determining their photocatalyzing performance. Herein, we report on the design and synthesis of BiVO4-rGO nanocomposites with efficient interfacial contact by self-assembly of positively charged amorphous BiVO4 powders with negatively charged graphene oxide (GO), followed by a one-step GO reduction and BiVO4 crystallization via hydrothermal treatment. The as-prepared BiVO4-rGO nanocomposites exhibit high visible light photocatalytic efficiency for the degradation of model dyes, and are significantly superior to bare crystalline BiVO4 and BiVO4-rGO-U that is hydrothermally synthesized using the mixture of GO nanosheets and BiVO4 powders without modification of surface charge. Using multiple characterization techniques, we found that the enhanced photocatalytic performance of BiVO4-rGO arises from the synergistic effects between the microscopic crystal structure of BiVO4 with smaller particle size and more sufficient interfacial interaction between BiVO4 and graphene sheets, leading to increased photocatalytic reaction sites, extended photoresponding range, enhanced photogenerated charge separation, and transportation efficiency. This work may provide a rational and convenient strategy to construct highly efficient semiconductor-rGO nanocomposite photocatalysts with well-contacted interface toward environmental purification and solar energy conversion.
通常认为，半导体还原氧化石墨烯（rGO）复合材料光催化剂的形貌和界面在决定其光催化性能方面起着至关重要的作用。在此，我们通过带正电荷的无定形 BiVO4 粉末与带负电荷的氧化石墨烯（GO）的自组装，设计并合成了具有高效界面接触的 BiVO4-rGO 纳米复合材料，然后通过水热处理一步还原 GO 和结晶 BiVO4。所制备的 BiVO4-rGO 纳米复合材料在降解模型染料方面表现出高可见光光催化效率，明显优于纯晶相 BiVO4 和 BiVO4-rGO-U，后者是使用 GO 纳米片和 BiVO4 粉末的混合物通过水热合成的，而没有对表面电荷进行修饰。通过多种表征技术，我们发现 BiVO4-rGO 的增强光催化性能源于 BiVO4 具有更小的颗粒尺寸和 BiVO4 与石墨烯片之间更充分的界面相互作用的微观晶体结构之间的协同效应，从而增加了光催化反应位点，扩展了光响应范围，增强了光生载流子分离和输运效率。这项工作可能为构建具有良好界面接触的高效半导体-rGO 纳米复合材料光催化剂提供了一种合理且方便的策略，可用于环境净化和太阳能转换。
