Xie Jing-Yi, Zhao Jie, Han Jun-Qi, Wang Fu-Li, Zhai Xue-Jun, Nan Jun, Wang Shu-Tao, Chai Yong-Ming, Dong Bin
State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China.
CNOOC Tianjin Chemical Research and Design Institute Co., Ltd, Tianjin 300131, China.
J Colloid Interface Sci. 2023 Dec 15;652(Pt B):1588-1596. doi: 10.1016/j.jcis.2023.08.194. Epub 2023 Sep 1.
The poor conductivities and instabilities of accessible nickel oxyhydroxides hinder their use as oxygen evolution reaction (OER) electrocatalysts. Herein, we constructed Fe-NiOOH-O-600, an Fe-doped nickel oxide hydroxide with abundant oxygen vacancies supported on nickel foam (NF), using a hydrothermal method and an electrochemical activation strategy involving 600 cycles of cyclic voltammetry, assisted by the precipitation/dissolution equilibrium of ferrous sulfide (FeS) in the electrolyte. This two-step method endows the catalyst with abundant Fe-containing active sites while maintaining the ordered structure of nickel oxide hydroxide (NiOOH). Characterization and density functional theory (DFT) calculations revealed that synergy between trace amounts of the Fe dopant and the oxygen vacancies not only promotes the generation of reconstructed active layers but also optimizes the electronic structure and adsorption capacity of the active sites. Consequently, the as-prepared Fe-NiOOH-O-600 delivered large current densities of 100 and 1000 mA cm for the OER at overpotentials of only 253 and 333 mV in 1 mol/L KOH. Moreover, the catalyst is stable for at least 100 h at 500 mA cm. This work provides insight into the design of efficient transition-metal-based electrocatalysts for the OER.
可获取的氢氧化氧镍的低导电性和不稳定性阻碍了其作为析氧反应（OER）电催化剂的应用。在此，我们采用水热法和一种电化学活化策略构建了Fe-NiOOH-O-600，一种负载在泡沫镍（NF）上的具有丰富氧空位的铁掺杂氢氧化镍，该策略涉及600次循环伏安法循环，并借助电解质中亚铁硫化物（FeS）的沉淀/溶解平衡。这种两步法赋予催化剂丰富的含铁活性位点，同时保持氢氧化镍（NiOOH）的有序结构。表征和密度泛函理论（DFT）计算表明，痕量铁掺杂剂与氧空位之间的协同作用不仅促进了重构活性层的生成，还优化了活性位点的电子结构和吸附能力。因此，制备的Fe-NiOOH-O-600在1 mol/L KOH中，对于OER在仅253和333 mV的过电位下分别提供了100和1000 mA cm的大电流密度。此外，该催化剂在500 mA cm下至少稳定100 h。这项工作为设计用于OER的高效过渡金属基电催化剂提供了思路。
