Construction of trimetallic metal-organic framework nanoarrays for efficient and stable oxygen evolution reaction

• Published in: International journal of hydrogen energy 2024-10, Vol.86, p.1278-1284
• Main Authors: Na, Guohao, Wu, Yuewen, Mei, Zhixin, Chen, Mingpeng, Dequan, Li, Sun, Huachuan, Chen, Yun, Zhou, Tong, Zhao, Jianhong, Zhang, Yumin, Zhang, Jin, Liu, Feng, Cui, Hao, Liu, Qingju
• Format: Article
• Language: English
• Subjects: Metal-organic framework; Oxygen evolution reaction; Self-reconstruction; Trimetallic catalyst
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2024.09.005

The slow kinetics of four-electron-transfer oxygen evolution reaction (OER) highly impedes the conversion efficiency of overall water splitting for green hydrogen production. Recently, metal-organic frameworks (MOFs) have attracted widespread attention due to their tunable morphologies, well-defined structures, and abundant metal sites. In this work, a series of cobalt-incorporated NiFe-MOF nanosheets were in-situ synthesized on nickel foam. Owing to the synergistic effect of exposed multi-metal sites, NiFeCo-BDC exhibits excellent OER activity, delivering an ultralow overpotential of 233 mV at the current density of 10 mA cm−2 with a small Tafel slope of 40.8 mV dec−1. In the continuous chronoamperometry test at 100 mA cm−2, almost no potential attenuation can be found over 200 h, demonstrating its remarkable stability. After OER, the amorphous metal oxyhydroxide layer is generated on surface, and the high-valent species are responsible for the superior OER performance. In-situ Raman spectra reveal that the organic ligands of NiFe-BDC and NiFeCo-BDC are etched and released during OER, and the Co incorporation facilitates the generation of amorphous layer. This work presents an effective strategy for design of multi-metal MOF-based electrocatalysts, and provides an insightful view on the structure evolution during OER. [Display omitted] •Construction of self-supported trimetallic NiFeCo-BDC nanoarrays.•Superior OER performance with ultra-low overpotential and excellent stability.•In-situ Raman studies on deciphering the self-reconstruction process.