Composition-Dependent Catalytic Activities of Noble-Metal-Free NiS/Ni3S4 for Hydrogen Evolution Reaction
详细信息 查看全文
- 作者：Zhixiao Qin ; Yubin Chen ; Zhenxiong Huang ; Jinzhan Su ; Zhidan Diao ; Liejin Guo
- 刊名：Journal of Physical Chemistry C
- 出版年：2016
- 出版时间：July 14, 2016
- 年：2016
- 卷：120
- 期：27
- 页码：14581-14589
- 全文大小：565K
- 年卷期：0
- ISSN：1932-7455
文摘
The development of efficient noble-metal-free hydrogen evolution catalysts is quite appealing with the aim of providing cost-competitive hydrogen. Herein, nickel sulfides (NiS<i>xi>) with tunable NiS/Ni3S4 molar ratios were synthesized via a simple hydrothermal method. Detailed electrochemical studies under neutral conditions indicated that the electrocatalytic property of NiS<i>xi> catalysts was determined by the composition. Notably, the NiS<i>xi> sample with the NiS/Ni3S4 molar ratio of 1.0 exhibited the lowest overpotential and charge-transfer resistance. As analyzed from the Tafel plots, the rate-determining step of NiS<i>xi> catalysts for hydrogen generation was the Volmer step, in which the proton adsorption played a key role. Theoretical calculation revealed that NiS and Ni3S4 exhibited the metallic behaviors with different work functions. Consequently, the NiS<i>xi> sample with the NiS/Ni3S4 molar ratio of 1.0 owned the most adsorbed protons, which led to the highest electrocatalytic property. Meanwhile, NiS<i>xi> was demonstrated to be efficient cocatalysts to promote photocatalytic hydrogen generation. NiS<i>xi>/CdS with the NiS/Ni3S4 molar ratio of 1.0 showed the best photocatalytic activity with the apparent quantum efficiency of 56.5% at 420 nm. This result was in good agreement with the electrocatalytic activities of NiS<i>xi> samples, indicating the intrinsic property for efficient hydrogen generation.