Metal Hydroxide-Organic Framework Mediated Structural Reengineering Enables Efficient NiFe Interaction for Robust Water Oxidation.

Liao, Hanxiao; Chen, Kejun; He, Xiaorong; Tong, Jiaxin; Liu, Xuanzhi; Tan, Pengfei; Guo, Xueyi; Pan, Jun · Nano Lett · 2024

basic_science · Level V

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Abstract

NiFe layered double hydroxide (NiFe LDH) derived oxyhydroxides are promising electrocatalysts for the alkaline oxygen evolution reaction (OER). However, NiFe LDH with a stable metal-oxygen-metal (M-O-M) structure suffers from inadequate NiFe interaction, leading to undesirable activity and stability. Herein, we develop a NiFe hydroxide-organic framework (NiFe HOF) via modification of NiFe LDH with an organic linker to break the structural constraint of M-O-M and thus boost the OER. NiFe HOF with reconfigurable metal sites facilitates structural reengineering under the OER condition to form abundant NiFe interaction and prolonged M-O bonds, stimulating lattice oxygen mechanism. Therefore, NiFe HOF shows a distinctly decreased overpotential at 50 mA cm<sup>-2</sup>, which is 68 mV lower than that of NiFe LDH. The anion exchange membrane electrolyzer using NiFe HOF as anode electrode displays ultralong stability exceeding 1050 h at 1 A cm<sup>-2</sup> with a low attenuation of 0.16 mV h<sup>-1</sup>.