Electronic structure modulation of nickel–iron layered double hydroxide via vanadium doping for enhanced oxygen evolution reaction performance

V 4+ /V 5+ doping optimizes the Ni/Fe d-band center in NiFe-LDH, weakening OH adsorption for superior OER. This yields a record-low overpotential of 254 mV and Tafel slope of 41.21 mV dec −1 , alongside a 40.8% lower R ct and 33% higher E CSA .