ZIF-8-derived porous carbon nanofibers anchoring NiFe-LDH for efficient oxygen evolution

The sluggish kinetics of the anodic oxygen evolution reaction (OER) severely limits the overall efficiency of water electrolysis. To overcome this critical bottleneck, we designed a self-supporting composite electrocatalyst by growing Ni-Fe layered double hydroxide (NiFe-LDH) nanosheets on zeolitic imidazolate framework-8 (ZIF-8) derived N doped porous carbon nanofibers (NCNFs). The in-situ pyrolysis process creates a dense, highly conductive mesoporous network within the carbon framework. Meanwhile, the vertical growth of NiFe-LDH helps alleviate catalyst agglomeration, thereby increasing active site exposure and accelerating mass transportation during reactions. Consequently, the optimized electrode exhibits excellent catalytic performance, achieving a low overpotential of 216 mV at 10 mA cm −2 , a Tafel slope of 62.3 mV dec −1 , and sustained long-term stability over 50 h at 50 mA cm −2 under the tested laboratory condition. Crucially, comprehensive density functional theory calculations rationalize the enhanced electrocatalytic kinetics by revealing strong interfacial electronic coupling. This unique electronic redistribution optimally upshifts the d band center of the active metal sites and significantly lowers the energy barrier of the rate-determining step from 2.14 eV to 1.56 eV. This work provides deep mechanistic insights and a feasible structural engineering strategy for developing highly efficient bimetallic electrocatalysts for future sustainable energy conversion applications.