Facet Engineering in Ultrathin Two-Dimensional NiFe Metal–Organic Frameworks by Coordination Modulation for Enhanced Electrocatalytic Water Oxidation

作者：Hongan Zhao, Lei Yu, Litong Zhang, Liming Dai, Fanglei Yao, Yin Huang, Jingwen Sun, Junwu Zhu · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2021 · DOI：10.1021/acssuschemeng.1c03385 · 被引用次数：68 · 研究领域：Electrocatalysts for Energy Conversion、Advanced battery technologies research、Electrochemical Analysis and Applications

Crystal facet engineering has been proved as a dramatically efficient strategy to optimize the intrinsic catalytic property of catalysts. However, because of the difficulty in precise construction, facet engineering of two-dimensional metal–organic frameworks (2D MOFs) is rarely reported. Herein, we propose a new and facile coordination modulation method to realize the controllable synthesis of 2D NiFe-MOFs with a highly exposed (001) crystal facet. Specifically, acetate ions, which possess the same coordination groups with the participated terephthalic ligand, have been adopted into the MOF construction as the morphology and facet regulator. Through competitive coordination effect and ion-induced self-assembly, the fabricated NiFe-MOFs reveal a hierarchical microsphere architecture consisting of ultrathin nanosheets with thickness ∼5 nm. Further benefiting from the structural advantages, e.g., abundant active sites, highly exposed catalytic facet, and enhanced mass/charge transport, the hierarchical NiFe-MOF nanosheets exhibit an attractive overpotential of 240 mV at the current density of 10 mA cm–2, a small Tafel slope of 73.44 mV dec–1, and satisfactory stability for 16 h toward oxygen evolution reaction (OER). Besides, the increased exposure of the (001) facet will increase the proportion of high-valent nickel oxyhydroxides during OER, which will enhance the electrocatalytic performance. The universality of the modulation method is further verified by the successful synt...