Metalloid tellurium-induced electron-deficient NiFe alloys awakening efficient oxygen electroreduction

Transition metal alloys catalysts have been extensively studied in oxygen reduction reactions (ORR); however, their suboptimal catalytic activity presents a significant challenge. Modifying the local electronic configuration of the catalytic active site by heteroatom doping is an effective strategy to enhance the electrocatalytic performance. Herein, an ORR Te/NiFe@NCNFs electrocatalyst, featuring with Te modified NiFe alloys nanoparticles and anchored on N-doped carbon nanofibers (NCNFs), was constructed via a surface-modified synthesis strategy. The introduction of Te leads to electron transfer on the surface of Te/NiFe@NCNFs, forming an electron-deficient NiFe site with high catalytic activity. Theoretical calculations confirm that Te regulates an electron redistribution and reduces the d-band centers of Fe and Ni, which help to facilitate the desorption of ORR intermediate oxides. As a result, Te/NiFe@NCNFs exhibit a half-wave potential of 0.86 V, superior to that of Pt/C (0.84 V) and most reported modified-NiFe-based catalysts. When assembled into a zinc-air battery, Te/NiFe@NCNFs deliver remarkable power density of 158.8 mW cm^-2-2 and specific capacity of 778.1 mA h g_Zn^-1. The present study presents new insights into the modulation of electronic structure in transition metal alloys, providing a feasible and innovative approach for the design of unrivaled ORR electrocatalysts.