Technical Center for Multifunctional Magneto-Optical Spectroscopy (ECNU), Shanghai Department of Electronic Engineering, East China Normal University, Shanghai 200241, China.
Sci Rep. 2017 Feb 13;7:42484. doi: 10.1038/srep42484.
The enhanced light-harvesting capacity and effective separation of photogenerated carriers in fantastic hierarchical heterostructures enjoy striking attention for potential applications in the field of solar cells and photocatalysis. A three-dimensional (3D) dandelion-shaped hierarchical BiS microsphere compactly decorated with wing-shaped few layered MoS lamella (D-BM) was fabricated via a facile hydrothermal self-assembly process. Especially, polyethylene glycol (PEG) has been proven as the vital template to form D-BM microsphere. Importantly, the as-prepared D-BM microsphere presents pH-dependent superior adsorption behavior and remarkable visible light photocatalytic activity for degradation of organic dyestuffs (Rhodamine B/RhB and Methylene blue/MB), far exceeding those for the pure BiS and MoS. It is understandable that D-BM with high surface area possesses more active sites and promotes light utilization due to the unique porous structure with outspread wings. Besides, based on the experiments and theoretical calculations, the staggered type II band alignment of D-BM permits the charge injection from BiS to MoS, subsequently accelerates the separation and restrains the recombination of carriers, leading to excellent photocatalytic activity, as well as the photoconductance and photoresponse performance (with I/I ratio 567).
在太阳能电池和光催化等领域，具有优异分层异质结构的增强光捕获能力和有效的光生载流子分离引起了人们的极大关注。通过简便的水热自组装工艺，制备了一种三维（3D）蒲公英状分层 BiS 微球，其紧密地装饰有翼状的少层 MoS 薄片（D-BM）。特别是，已经证明聚乙二醇（PEG）是形成 D-BM 微球的重要模板。重要的是，所制备的 D-BM 微球具有 pH 依赖性的优异吸附行为和显著的可见光光催化活性，可用于降解有机染料（罗丹明 B/RhB 和亚甲蓝/MB），远远超过纯 BiS 和 MoS 的性能。可以理解的是，由于具有扩展翼的独特多孔结构，具有高表面积的 D-BM 具有更多的活性位点并促进了光的利用。此外，基于实验和理论计算，D-BM 的交错型 II 型能带排列允许电荷从 BiS 注入到 MoS，从而加速了载流子的分离并抑制了载流子的复合，从而具有优异的光催化活性，以及光电导和光响应性能（I/I 比为 567）。
