Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
Central European Institute of Technology, Brno University of Technology, Purkynova 123, 61200, Brno, Czech Republic.
Chemistry. 2018 Dec 10;24(69):18551-18555. doi: 10.1002/chem.201804821. Epub 2018 Nov 21.
Transition metal dichalcogenides (TMDs) have recently emerged within the group of 2D materials due to their electrical, catalytic and optical properties significantly enhanced and useful when down-sized to single layer. In particular, MoS has attracted much attention due to its semiconducting nature with a useful band gap when present as single layer, the enhanced photoluminescence, but also importantly the excellent catalytic properties towards the electrochemical hydrogen evolution. We present here the preparation of thin layers MoS nanosheets with enhanced catalytic properties towards the hydrogen evolution reaction by means of an easy and fast electrochemical top-down exfoliation procedure in aqueous solution from a naturally occurring MoS crystal. After structural and chemical characterization with STEM, AFM, XPS and Raman spectroscopy electrochemical investigations were performed to test catalytic properties in acidic solution for the electrogeneration of hydrogen and compare it to MoS nanosheets obtained through the widely employed chemical Li intercalation/exfoliation. Electrochemically exfoliated MoS shows lower Tafel slope than its counterpart obtained with chemical exfoliation.
过渡金属二硫属化物（TMDs）由于其电学、催化和光学性质在单层时得到显著增强，因此在二维材料中崭露头角。特别是，MoS 由于其半导体性质，在单层时具有有用的带隙，增强的光致发光，以及对电化学析氢反应的优异催化性能，引起了广泛的关注。我们在这里提出了一种简单快速的电化学自上而下剥离方法，从天然 MoS 晶体在水溶液中制备具有增强析氢反应催化性能的薄 MoS 纳米片。通过 STEM、AFM、XPS 和拉曼光谱进行结构和化学表征后，进行了电化学研究以测试酸性溶液中用于电生成氢气的催化性能，并将其与通过广泛采用的化学插层/剥离法获得的 MoS 纳米片进行比较。电化学剥离的 MoS 表现出比化学剥离获得的 MoS 更低的塔菲尔斜率。
