Hefei National Laboratory of Physical Sciences at the Microscale, University of Science and Technology of China (USTC), Hefei 230026, Anhui, P. R. China.
Nanoscale. 2014 Oct 7;6(19):11046-51. doi: 10.1039/c4nr02716g.
MoSe2 nanosheets have been extensively pursued due to the outstanding properties of this typical layered transition metal dichalcogenide (LTMD). In this work, we report a facile, fast strategy to synthesize scalable hierarchical ultrathin MoSe2-x (x ∼ 0.47) nanosheets. The nanosheets possess 2-5 Se-Mo-Se atomic layers and were synthesised through a bottom-up colloidal route within 20 mins under mild conditions from the reaction of MoO2(acac)2 with dibenzyl diselenide. The as-obtained hierarchical ultrathin MoSe2-x nanosheets are Mo-rich with a Se vacancy and show excellent HER performance with a small overpotential of ∼170 mV, large cathodic currents, and a Tafel slope of 98 mV per decade. Such high performance has been attributed to the unique structure of the Se vacancy defect, large surface area, as well as the enhanced conductivity. Meanwhile, the pathway can be extended as a general strategy to prepare other metal selenides, such as ultrathin WSe2 and SnSe nanosheets, and PbSe nanocrystals. It will also pave a new way to synthesize scalable nanostructured materials for intriguing nanodevices and large-scale applications.
由于典型的层状过渡金属二卤化物 (LTMD) 的出色性能，MoSe2 纳米片得到了广泛的研究。在这项工作中，我们报告了一种简便、快速的策略，可合成可扩展的分层超薄 MoSe2-x（x∼0.47）纳米片。纳米片具有 2-5 个 Se-Mo-Se 原子层，通过 MoO2(acac)2 与二苄基二硒化物之间的自下而上胶体途径在温和条件下于 20 分钟内合成。所获得的分层超薄 MoSe2-x 纳米片是富 Mo 且具有 Se 空位的，具有优异的 HER 性能，过电位约为 170 mV，阴极电流较大，塔菲尔斜率为 98 mV/decade。这种高性能归因于 Se 空位缺陷的独特结构、大表面积以及增强的导电性。同时，该途径可以扩展为一种通用策略，用于制备其他金属硒化物，如超薄 WSe2 和 SnSe 纳米片以及 PbSe 纳米晶体。它还将为合成用于有趣的纳米器件和大规模应用的可扩展纳米结构材料开辟新途径。
