Zhang Junjun, Zhang Chenhui, Wang Zhenyu, Zhu Jian, Wen Zhiwei, Zhao Xingzhong, Zhang Xixiang, Xu Jun, Lu Zhouguang
Shenzhen Key Laboratory of Hydrogen Energy and Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, P. R. China.
School of Physics and Technology, Wuhan University, Wuhan, 430072, P. R. China.
Small. 2018 Mar;14(9). doi: 10.1002/smll.201703098. Epub 2017 Dec 27.
A simple one-pot solvothermal method is reported to synthesize VS nanosheets featuring rich defects and an expanded (001) interlayer spacing as large as 1.00 nm, which is a ≈74% expansion as relative to that (0.575 nm) of the pristine counterpart. The interlayer-expanded VS nanosheets show extraordinary kinetic metrics for electrocatalytic hydrogen evolution reaction (HER), exhibiting a low overpotential of 43 mV at a geometric current density of 10 mA cm , a small Tafel slope of 36 mV dec , and long-term stability of 60 h without any current fading. The performance is much better than that of the pristine VS with a normal interlayer spacing, and even comparable to that of the commercial Pt/C electrocatalyst. The outstanding electrocatalytic activity is attributed to the expanded interlayer distance and the generated rich defects. Increased numbers of exposed active sites and modified electronic structures are achieved, resulting in an optimal free energy of hydrogen adsorption (∆G ) from density functional theory calculations. This work opens up a new door for developing transition-metal dichalcogenide nanosheets as high active HER electrocatalysts by interlayer and defect engineering.
据报道，一种简单的一锅溶剂热法可合成具有丰富缺陷且（001）层间距扩大至1.00 nm的VS纳米片，相对于原始对应物（0.575 nm）的层间距，其扩大了约74%。层间距扩大的VS纳米片在电催化析氢反应（HER）中表现出非凡的动力学指标，在几何电流密度为10 mA cm时，过电位低至43 mV，塔菲尔斜率小至36 mV dec，并且具有60小时的长期稳定性且无电流衰减。该性能远优于具有正常层间距的原始VS，甚至可与商业Pt/C电催化剂相媲美。出色的电催化活性归因于扩大的层间距和产生的丰富缺陷。通过密度泛函理论计算，实现了更多暴露的活性位点和改性的电子结构，从而获得了最佳的氢吸附自由能（∆G）。这项工作为通过层间和缺陷工程开发作为高活性HER电催化剂的过渡金属二硫属化物纳米片打开了一扇新的大门。
