Xing Minghui, Wang Shitao, Yun Jimmy, Cao Dapeng
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China.
Qingdao International Academician Park Research Institute, Qingdao, 266000, China.
Small. 2024 Nov;20(46):e2402852. doi: 10.1002/smll.202402852. Epub 2024 Aug 9.
The seawater electrolysis to produce hydrogen is a significant topic on alleviating the energy crisis. Here, the Fe, Nb-NiS catalyst is prepared by metal-doping strategy, and it shows high oxygen evolution reaction (OER) activity in alkaline medium, and only needs 1.491 V to deliver a current density of 100 mA cm in simulated seawater. Using Fe, Nb-NiS as a bifunctional catalyst, the two-electrode electrolyzer only requires a voltage of 1.751 V (without impedance compensation) to drive the current density of 50 mA cm, and can run over 150 h stably in the simulated seawater. Importantly, In situ Raman test demonstrates that the outstanding performance of Fe, Nb-NiS in simulated seawater is ascribed to the in situ formed sulfate protective layer induced by Nb doping, which can effectively inhibit the corrosion of chloride ion, while the protective layer is absent for Fe-NiS. The stable operation of simulated seawater electrolysis under industrial current density further confirms the stability improvement mechanism of forming protective layer. In short, this study provides a new strategy of using Nb dopants inducing the formation of protective layer to enhance the stability of seawater electrolysis.
海水电解制氢是缓解能源危机的一个重要课题。在此，通过金属掺杂策略制备了Fe、Nb-NiS催化剂，其在碱性介质中表现出高析氧反应（OER）活性，在模拟海水中仅需1.491 V即可达到100 mA cm的电流密度。以Fe、Nb-NiS作为双功能催化剂，两电极电解槽仅需1.751 V（无阻抗补偿）的电压即可驱动50 mA cm的电流密度，并且在模拟海水中可稳定运行超过150 h。重要的是，原位拉曼测试表明，Fe、Nb-NiS在模拟海水中的优异性能归因于Nb掺杂诱导原位形成的硫酸盐保护层，该保护层可有效抑制氯离子的腐蚀，而Fe-NiS则不存在该保护层。在工业电流密度下模拟海水电解的稳定运行进一步证实了形成保护层的稳定性提高机制。总之，本研究提供了一种利用Nb掺杂剂诱导形成保护层以提高海水电解稳定性的新策略。
