Zhang Xiaowen, Zhang Yijie, Gao Yuan, Zhao Qiang, Li Jinping, Liu Guang
Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China.
Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, College of Chemical Engineering and Technology, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China; Shanxi Research Institute of HuaiRou Laboratory, Taiyuan, Shanxi 030031, China.
J Colloid Interface Sci. 2025 Feb;679(Pt A):607-614. doi: 10.1016/j.jcis.2024.10.026. Epub 2024 Oct 6.
In alkaline water splitting, transition metals (Ni, Fe) have received extensive attention, and NiFe-oxyhydroxide (NiFeOOH) is regarded as an exceptionally active electrocatalysts for oxygen evolution reaction (OER). However, maintaining the long-term stability of NiFeOOH at high current densities is challenging due to Fe segregation and catalyst degradation. Herein, this study proposes an approach to enhancing the stability of the Ni/Fe-O covalent bond by intercalating oxyanions (NO, PO, SO, and SeO) into the NiFeOOH substrate, improving its resistance to bond breakage. And the NiFeOOH-NO- electrocatalyst was found to be optimal, achieving an overpotential of 311 mV and stable performance at 1 A cm for several hundred hours. Consequently, NiFeOOH-NO exhibited a significantly improved OER stability, with a mere 3.33 % stability attenuation after 100 h, compared to 13.19 % for pristine NiFeOOH. Notably, the presence of NO in NiFeOOH effectively mitigates Fe segregation, leading to a fourfold enhancement in long-term stability relative to that of NiFeOOH without NO modification. Theoretical calculations show that the introduction of NO effectively shifts metal 3d band centers of NiFeOOH closer to the Fermi level. It is suggested that the oxyanions lead to increased strength of the Ni/Fe-O bonds, thereby inhibiting the dissolution of Fe and enhancing the stability of NiFeOOH phase. This research represents a significant advance in controlling Fe segregation to stabilize NiFe-based electrocatalysts for high-current-density water oxidation.
在碱性水分解中，过渡金属（镍、铁）受到了广泛关注，并且氢氧化镍铁（NiFeOOH）被视为析氧反应（OER）极具活性的电催化剂。然而，由于铁的偏析和催化剂降解，在高电流密度下维持NiFeOOH的长期稳定性具有挑战性。在此，本研究提出一种通过将氧阴离子（NO、PO、SO和SeO）嵌入NiFeOOH基底来增强Ni/Fe-O共价键稳定性的方法，提高其抗键断裂能力。并且发现NiFeOOH-NO电催化剂是最优的，在1 A cm-2下实现了311 mV的过电位和数百小时的稳定性能。因此，NiFeOOH-NO表现出显著提高的OER稳定性，100小时后稳定性衰减仅为3.33%，而原始NiFeOOH为13.19%。值得注意的是，NiFeOOH中NO的存在有效减轻了铁的偏析，相对于未进行NO修饰的NiFeOOH，长期稳定性提高了四倍。理论计算表明，NO的引入有效地使NiFeOOH的金属3d带中心更接近费米能级。这表明氧阴离子导致Ni/Fe-O键强度增加，从而抑制铁的溶解并增强NiFeOOH相的稳定性。这项研究在控制铁偏析以稳定用于高电流密度水氧化的镍铁基电催化剂方面取得了重大进展。
