Wu Bin, Gong Shun, Lin Yichao, Li Tao, Chen Anyang, Zhao Mengyuan, Zhang Qiuju, Chen Liang
Key Laboratory of Advanced Fuel Cells and Electrolyzers Technology of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, 315201, P. R. China.
Department of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Adv Mater. 2022 Oct;34(43):e2108619. doi: 10.1002/adma.202108619. Epub 2022 Sep 25.
The development of highly efficient non-precious metal electrocatalysts for the oxygen evolution reaction (OER) in low-grade or saline water is currently of great importance for the large-scale production of hydrogen. In this study, by using an electrochemical activation pretreatment, metal oxy(hydroxide) nanosheet structures derived from self-supported nickel-iron phosphide and nitride nanoarrays grown on Ni foam are successfully fabricated for OER catalysis in saline water. It is demonstrated that the different NiOOH and NiOOH@FeOOH (NiOOH grown on FeOOH) structures are generated from nickel-iron nitride and phosphide, respectively, after electrochemical activation. In particular, the NiOOH@FeOOH heteroarchitecture shows outstanding electrocatalytic performance with an ultralow overpotential of 292 mV to drive the current density of 500 mA cm . An unconventional dual-sites mechanism (UDSM) is proposed to address the OER process on NiOOH@FeOOH and show that the FeOOH underlayer plays a critical role regarding the enhanced OER activity of NiOOH. The new possible UDSM involving two reaction sites presents a different understanding of the OER process on multi-OH layer complexes, which is expected to guide the design of heteroarchitecture electrocatalysts.
开发用于在低品位水或盐水中进行析氧反应（OER）的高效非贵金属电催化剂对于大规模制氢目前具有重要意义。在本研究中，通过电化学活化预处理，成功制备了由生长在泡沫镍上的自支撑镍铁磷化物和氮化物纳米阵列衍生而来的金属氧（氢氧）化物纳米片结构，用于盐水中的OER催化。结果表明，电化学活化后，镍铁氮化物和磷化物分别生成了不同的NiOOH和NiOOH@FeOOH（在FeOOH上生长的NiOOH）结构。特别是，NiOOH@FeOOH异质结构表现出优异的电催化性能，驱动500 mA cm电流密度时的过电位低至292 mV。提出了一种非常规双位点机制（UDSM）来解释NiOOH@FeOOH上的OER过程，并表明FeOOH底层对增强NiOOH的OER活性起着关键作用。涉及两个反应位点的新的可能的UDSM对多OH层络合物上的OER过程提出了不同的理解，有望指导异质结构电催化剂的设计。
