Composition-dependent electrocatalytic activities of NiFe-based selenides for the oxygen evolution reaction

Exploring low-cost and high-efficient electrocatalysts for oxygen evolution reaction (OER) is still an ongoing challenge to substitute noble metal materials. In this work, NiFe-based selenide (Ni-Fe-Se) is synthesized by hydrothermal treatment of metal-organic frameworks (MOFs) and Se powder. The effects of hydrothermal temperature and mass ratio of precursors on the decomposition and selenization of MOFs were investigated. Compared with NiFe based oxide, Ni-Fe-Se is favorable for improving the electronic conductivity and reduce the charge transfer resistance, promoting the formation of the higher oxidative valence of Ni species during OER process. Benefiting from the desirable advantages with unique composition, the Ni-Fe-Se material prepared under optimal conditions shows excellent electrocatalytic activities toward OER with the lower overpotential of 216 mV at a current density of 10 mA cm−2. Besides, the resulting Ni-Fe-Se catalyst exhibits excellent durability when used as air cathode in Zn-air battery.