Ultralong Metal–Organic Framework Nanowires with Accelerated Reconstruction for Enhanced Oxygen Evolution Reaction

Many transition-metal-based catalysts, including metal–organic frameworks (MOFs), usually undergo reconstruction to form catalytically active oxyhydroxide sites during the oxygen evolution reaction (OER). However, structural transformation of conventional bulk MOFs mostly occurs at the surface, while internal active centers are not utilized, limiting the improvement in electrocatalytic performance. Herein, we demonstrate that reducing the MOF dimension can accelerate the transformation to metal oxyhydroxides and boost the OER activity. An ultralong NiCo-MOF-74 nanowire (NiCo-MOF-74-NW) enriched with surface open metal sites is prepared by a “pre-assembly–crystallization” strategy. Structural characterization and in situ analysis reveal that the nanowire morphology facilitates reconstruction into active CoOOH species during electrocatalysis. NiCo-MOF-74-NW achieves a low overpotential of 292 mV at 100 mA cm –2, along with enhanced intrinsic activity and favorable reaction kinetics compared to MOF microrods (NiCo-MOF-74-MR). This work provides insights for designing MOF-based electrocatalysts through the decrease of dimensions to promote surface reconstruction.