Transition-metal-dependent electronic structure and intrinsic oxygen evolution activity of Mn-, Cu-, and Ni-based tellurium oxides

Developing efficient and earth-abundant electrocatalysts for oxygen evolution reaction (OER) is crucial for reducing energy consumption of water electrolysis. Although transition-metal tellurium oxides possess tunable electronic structures and metal–oxygen–tellurium interactions, influence of metal species on OER activity remains unclear. Herein, manganese tellurium oxide (MnTeO), copper tellurium oxide (CuTeO), and nickel tellurium oxide (NiTeO) are synthesized via hydrothermal and thermal oxidation processes to investigate metal-dependent structure–activity relationships. Metal species regulate phase composition, morphology, surface electronic structures, and electrochemical properties. MnTeO exhibits the best OER performance, requiring overpotentials of 352.2, 371.2, and 386.4 mV at 10, 20, and 40 mA cm −2 , respectively, with a low Tafel slope of 49.9 mV dec −1 . MnTeO delivers high electrocatalytic activity, low charge-transfer resistance, 99.3% Faradaic efficiency, and 64.8% current retention after 50 h. Superior performance of MnTeO is associated with its favorable surface electronic environment, mixed-valence Mn states, and efficient interfacial charge-transfer characteristics.