Institute of Special Materials and Technology, Fudan University, 200433, Shanghai, China.
Nanoscale. 2017 May 4;9(17):5538-5544. doi: 10.1039/c6nr09977g.
Transition metal dichalcogenides, MX (M = Fe, Co, Ni, X = S, Se, Te), have been proven to be promising substitutes for noble metals in hydrogen evolution reactions (HERs). However, forthright comparisons of metal sulfides, metal selenides, and metal tellurides are rarely conducted, let alone the mechanism of the important role of their non-metal ligands. In this paper, we report the pilot study of a controllable method for the preparation of a series of NiX (X = S, Se, Te) nanosheets via a facile anion-exchange reaction. Consequently, the HER activities and stabilities of NiS, NiSe, and NiTe nanosheets were tested in both acid and alkaline solutions. The required overpotentials to reach 10 mA cm in 0.5 M HSO for NiS, NiSe, and NiTe were 213, 156, and 276 mV, respectively. The best performance of NiSe was also confirmed in 1 M KOH. Besides NiS and NiTe nanosheets, the HER properties of NiSe nanosheets are superior to most of the available nickel catalysts. Interestingly, the results from electrochemical measurements were found to be fully consistent with the data based on density function theory calculation. Among various factors that might influence the HER activities of nickel dichalcogenides, the free energies of hydrogen adsorption and conductivities have played important roles.
过渡金属二卤化物，MX（M=Fe、Co、Ni、X=S、Se、Te）已被证明是在析氢反应（HER）中替代贵金属的很有前途的材料。然而，很少对金属硫化物、硒化物和碲化物进行直接比较，更不用说它们的非金属配体的重要作用的机制了。在本文中，我们报告了一种通过简单的阴离子交换反应制备一系列 NiX（X=S、Se、Te）纳米片的可控方法的初步研究。因此，在酸性和碱性溶液中测试了 NiS、NiSe 和 NiTe 纳米片的 HER 活性和稳定性。在 0.5 M HSO 中达到 10 mA cm 需要的过电位分别为 213、156 和 276 mV。在 1 M KOH 中，NiSe 的性能也得到了最佳验证。除了 NiS 和 NiTe 纳米片外，NiSe 纳米片的 HER 性能优于大多数可用的镍催化剂。有趣的是，电化学测量的结果与基于密度泛函理论计算的数据完全一致。在可能影响镍二卤化物析氢活性的各种因素中，氢吸附自由能和电导率起着重要作用。
