Tailoring the electrocatalytic activity of bimetallic nickel-iron diselenide hollow nanochains for water oxidation

Exploring low-cost, high-efficient and durable electrocatalysts to substitute for Ru, Ir-based noble metal catalysts is of great significance for oxygen evolution reaction (OER), which is in particular a sluggish anodic process in water oxidation and remains to be a major challenge that we are confronted with. Herein, we report nickel-iron diselenide hollow nanochains (denoted as NFSHNCs) synthesized via a two-step hydrothermal method working as the high performance OER catalyst. The formation of well-shaped NFSHNCs is due to the Kirkendall effect, in which NiFe alloy solid nanochains were employed as the precursors. The as-prepared NFSHNCs not only exhibit outstanding OER performance with low overpotential of 267 mV (at a current density of 10 mA cm(-2)) and small Tafel slope of 67 mV dec(-1), superior to the state-of-the-art commercial RuO2, but also deliver high durability with a dinky degradation of 5.3% after 12 h fierce test. To identify the electrocatalytic active sites, the Gibbs free energy differences (Delta G) related to the O* and OH* adsorption on NiFe selenides were calculated with density functional theory. The theoretical results corroborate the fact that the O* and OH* adsorption prefers to occur on both iron sites and the nickel sites (the one that in the vicinity of iron sites) because of the synergistic effects of electron configuration.