Surface selectivity of Ni3S2 toward hydrogen evolution reaction: a first-principles study
Surface selectivity of Ni3S2 toward hydrogen evolution reaction: a first-principles study
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Ni3S2 对析氢反应的表面选择性：第一性原理研究
DOI：
10.1039/d0cp03845h
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发表时间：
2020
影响因子：
3.3
通讯作者：
Wu Xiaojun
中科院分区：
文献类型：
--
作者：
Zhang Bo;Fu Xiuli;Song Li;Wu Xiaojun
探索具有高析氢反应催化性能的材料对开发清洁氢能源具有重要意义，而其表面结构是实现这一功能的关键。本文利用密度泛函理论（DFT）对Ni3S2（0001）、（100）、（101）、（110）、（111）等不同端部的低折射率表面的相稳定性、表面结构、电子性能和HER催化性能进行了全面研究。我们的计算结果表明，Ni3S2的富s表面和几种化学计量表面(包括（0001）A、（100）A、（110）C、（100）C、（100）B和（111）A表面都是热力学稳定的。在六种稳定的表面结构中，Ni3S2的（0001）A、（100）B和（100）C表面结构具有较高的催化活性、适宜的电位和较高的热力学稳定性，是提高HER性能必不可少的结构。计算得到（0001）A上的Top S2位点、（100）C上的Hollow Ni2S3S4位点、（100）B上的Bridge Ni1Ni3位点和Hollow Ni2S1S2位点的Gibbs自由能变化（ΔGH*）分别为- 0.143、0.122、0.012和- 0.112 eV，与Pt（111）的Gibbs自由能变化（- 0.07 eV）相当甚至更好。此外，还研究了所考虑的表面上可能存在的Volmer-Heyrovsky和Volmer-Tafel过程。当过电位在0 ~ 300 mV范围内时，Ni3S2 (100)B表面活性位点密度最大。这项工作为Ni3S2对HER的表面选择性提供了重要的见解，并为优化Ni3S2暴露表面的性能提供了一条途径。
Exploring materials with high catalytic performance toward hydrogen evolution reaction (HER) is of importance for the development of clean hydrogen energy, and their surface structure is essential for this function. In this study, using density functional theory (DFT), we reported a comprehensive study on the phase stability, surface structures, electronic properties and HER catalytic properties of the low-index surfaces of Ni3S2, including the (0001), (100), (101), (110) and (111) planes with different terminations. Our calculated results demonstrate that S-rich surfaces and several stoichiometric surfaces of Ni3S2 are thermodynamically stable, including (0001)A, (100)A, (110)C, (100)C, (100)B and (111)A surfaces. Among the six stable surface structures, the (0001)A, (100)B and (100)C surfaces of Ni3S2 are indispensable for high HER performance because of their high catalytic activity, suitable potential and high thermodynamic stability. The calculated changes of Gibbs free energy (ΔGH*) of the Top S2 site on (0001)A, Hollow Ni2S3S4 site on (100)C, and Bridge Ni1Ni3 site and Hollow Ni2S1S2 site on (100)B are −0.143, 0.122, 0.012, and −0.112 eV, respectively, comparable with or even better than those of Pt(111) (−0.07 eV). In addition, the possible Volmer–Heyrovsky and Volmer–Tafel processes on the considered surfaces are also investigated. When the overpotential is in the range of 0 to 300 mV, the density of active sites on the (100)B surface of Ni3S2 is found to be the highest. This work provides significant insights on the surface selectivity of Ni3S2 toward HER and provides a route to optimize the performance of Ni3S2 with exposed surfaces.