Heterogeneous Spin States in Ultrathin Nanosheets Induce Subtle Lattice Distortion To Trigger Efficient Hydrogen Evolution

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• 作者：Youwen Liu ; Xuemin Hua ; Chong Xiao ; Tengfei Zhou ; Pengcheng Huang ; Zaiping Guo ; Bicai Pan ; Yi Xie
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：April 20, 2016
• 年：2016
• 卷：138
• 期：15
• 页码：5087-5092
• 全文大小：478K
• 年卷期：0
• ISSN：1520-5126

文摘

The exploration of efficient nonprecious metal eletrocatalysis of the hydrogen evolution reaction (HER) is an extraordinary challenge for future applications in sustainable energy conversion. The family of first-row-transition-metal dichalcogenides has received a small amount of research, including the active site and dynamics, relative to their extraordinary potential. In response, we developed a strategy to achieve synergistically active sites and dynamic regulation in first-row-transition-metal dichalcogenides by the heterogeneous spin states incorporated in this work. Specifically, taking the metallic Mn-doped pyrite CoSe₂ as a self-adaptived, subtle atomic arrangement distortion to provide additional active edge sites for HER will occur in the CoSe₂ atomic layers with Mn incorporated into the primitive lattice, which is visually verified by HRTEM. Synergistically, the density functional theory simulation results reveal that the Mn incorporation lowers the kinetic energy barrier by promoting H–H bond formation on two adjacently adsorbed H atoms, benefiting H₂ gas evolution. As a result, the Mn-doped CoSe₂ ultrathin nanosheets possess useful HER properties with a low overpotential of 174 mV, an unexpectedly small Tafel slope of 36 mV/dec, and a larger exchange current density of 68.3 μA cm^–2. Moreover, the original concept of coordinated regulation presented in this work can broaden horizons and provide new dimensions in the design of newly highly efficient catalysts for hydrogen evolution.