Yang Yuying, Meng Haixia, Kong Chao, Yan Shaohui, Ma Weixia, Zhu Hong, Ma Fuquan, Wang Chengjuan, Hu Zhongai
Key Laboratory of Eco-Environment-Related Polymer Materials of Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, PR China.
Key Laboratory of Eco-Environment-Related Polymer Materials of Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, PR China.
J Colloid Interface Sci. 2021 Oct;599:300-312. doi: 10.1016/j.jcis.2021.04.004. Epub 2021 Apr 20.
Developing and designing bifunctional electrocatalysts are very important for the production of hydrogen from water electrolysis. The reasonable interface modulation can effectively lead to the optimization of electronic configuration through the interface electron transfer in the heterostructures and thus resulting in the enhanced efficiency. In this work, self-supported and heterogeneous interface-rich NiS@FeNiS@NF electrocatalyst for overall water splitting was designed and prepared through a controllable step-wise hydrothermal process. Density functional theory calculations suggest that heterogeneous interface formed between NiS and FeNiS can optimize the Gibbs free energy for H* adsorption (ΔG). Benefiting from the open structure of the nanosheet arrays, the abundant heterogeneous interfaces in NiS@FeNiS@NF composite, the positive synergistic effect between NiS and FeNiS, and the good conductivity of foamed nickel (NF) substrate, the optimized NiS@FeNiS@NF nanoarray catalyst displayed excellent electrocatalytic activities, the overpotential is only 83 mV and 235 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at 10 mA cm, respectively. Importantly, an alkaline electrolyser directly using the NiS@FeNiS@NF as both the anode and cathode achieved an ultralow cell voltage of 1.46 V, accompanied by outstanding stability. The performance is better than that of most other transition-metal sulfides electrocatalysts. This work may provide a useful strategy for reasonably regulating heterogeneous interfaces to effectively improve the performance of materials, thus accelerating the practical application of transition-metal sulfides electrocatalysts for overall water splitting.
开发和设计双功能电催化剂对于水电解制氢非常重要。合理的界面调控能够通过异质结构中的界面电子转移有效地优化电子构型，从而提高效率。在本工作中，通过可控的分步水热法设计并制备了用于全水解的自支撑且富含异质界面的NiS@FeNiS@NF电催化剂。密度泛函理论计算表明，NiS与FeNiS之间形成的异质界面能够优化H*吸附的吉布斯自由能（ΔG）。得益于纳米片阵列的开放结构、NiS@FeNiS@NF复合材料中丰富的异质界面、NiS与FeNiS之间的正协同效应以及泡沫镍（NF）基底的良好导电性，优化后的NiS@FeNiS@NF纳米阵列催化剂展现出优异的电催化活性，在10 mA cm下析氢反应（HER）和析氧反应（OER）的过电位分别仅为83 mV和235 mV。重要的是，直接使用NiS@FeNiS@NF作为阳极和阴极的碱性电解槽实现了1.46 V的超低电池电压，同时具有出色的稳定性。该性能优于大多数其他过渡金属硫化物电催化剂。这项工作可能为合理调控异质界面以有效提高材料性能提供一种有用的策略，从而加速过渡金属硫化物电催化剂用于全水解的实际应用。
