Te-doped NiFe2O4 stabilized by amorphous carbon layers derived from one-step topological transitions of NiFe LDHs with significantly enhanced oxygen evolution reaction

Constructing efficient oxygen evolution reaction (OER) electrocatalysts that can stably operate under high temperatures and strong alkaline conditions still faces great challenges for industrial hydrogen production from water electrolysis. Herein, a self-supported tellurium (Te)-doped spinel NiFe2O4 with a carbon-stabilized nanosheet structure anodic catalyst on nickel foam (NF) (Te-NiFe2O4@C/NF) is successfully synthesized by calcination of a layered double hydroxide precursor (NiFe LDH). Benefiting from Te doping as well as coupling with the amorphous carbon layer and the unique superhydrophilic/aerophobic surface property, which provides efficient mass transport channels and rapid electron transport, the optimized Te-NiFe2O4@C/NF requires an overpotential of 220 mV to achieve a current density of 10 mA cm−2 for the OER in 1 M KOH at 25 ℃. Furthermore, an extremely low overpotential of 180 mV is required to achieve 500 mA cm−2 in 6 M KOH at 80 ℃ and maintains superior stability over 60 h under such harsh quasi-industrial conditions. Density functional theory calculations further reveal that Te doping can effectively modulate the local electronic environment of the Ni and Fe sites, which optimizes the intermediate (*OH) adsorption and facilitates the OER kinetics. This work may open up opportunities to explore efficient electrocatalysts for scalable hydrogen production.