Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China.
School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China.
Nat Commun. 2018 Apr 12;9(1):1425. doi: 10.1038/s41467-018-03858-w.
Metal sulfides for hydrogen evolution catalysis typically suffer from unfavorable hydrogen desorption properties due to the strong interaction between the adsorbed H and the intensely electronegative sulfur. Here, we demonstrate a general strategy to improve the hydrogen evolution catalysis of metal sulfides by modulating the surface electron densities. The N modulated NiCoS nanowire arrays exhibit an overpotential of 41 mV at 10 mA cm and a Tafel slope of 37 mV dec, which are very close to the performance of the benchmark Pt/C in alkaline condition. X-ray photoelectron spectroscopy, synchrotron-based X-ray absorption spectroscopy, and density functional theory studies consistently confirm the surface electron densities of NiCoS have been effectively manipulated by N doping. The capability to modulate the electron densities of the catalytic sites could provide valuable insights for the rational design of highly efficient catalysts for hydrogen evolution and beyond.
金属硫化物在用于析氢催化时通常由于吸附氢和强电负性硫之间的强相互作用而具有不利的氢脱附性质。在这里，我们通过调节表面电子密度来证明一种提高金属硫化物析氢催化性能的通用策略。氮调制的 NiCoS 纳米线阵列在 10 mA cm 时表现出 41 mV 的过电势和 37 mV dec 的塔菲尔斜率，这非常接近碱性条件下基准 Pt/C 的性能。X 射线光电子能谱、基于同步加速器的 X 射线吸收光谱和密度泛函理论研究一致证实，氮掺杂有效地调节了 NiCoS 的表面电子密度。这种调节催化位点电子密度的能力为合理设计高效析氢催化剂以及超越析氢反应的催化剂提供了有价值的见解。
