Phase Transition Engineering of Metal–Organic Frameworks Induces Multiphase Complexation for Enhancing the Oxygen Evolution Reaction
Ke Xu, Jie Yin, Linzi Li, Xiaozhen Li, Xiaolong Liang, Jing Liang, Jun Lü, Zhiwen Liu, Huanyue Zhang, Tianming Lv, Xueliang Mu, Jinxuan Liu
Abstract
Phase transition engineering of metal–organic frameworks (MOFs) presents a promising strategy for enhancing electrocatalytic performance in water splitting applications. In this study, we demonstrate a controlled phase transition strategy to synthesize a multiphase composite (op&cp) composed of open phase (op) and closed phase (cp) through precise desolvation treatment. When used as an alkaline water electrocatalyst, op&cp exhibits exceptional oxygen evolution reaction (OER) performance, achieving a remarkably low overpotential of 140 mV under 10 mA cm –2 and maintaining stable operation for over 75 h at 100 mA cm –2 . In situ Raman spectroscopy and X-ray photoelectron spectroscopy show that the catalytically active substance NiOOH is formed on the engineered phase with a lower potential (1.2 V vs RHE) than the single-phase material (1.3 V vs RHE). This work establishes phase transition engineering as a viable strategy for improving MOF-based catalysis and explores the fundamental mechanism of the dynamic evolution of active sites during the OER.