Green hydrogen production through electrochemical water splitting is one of the optimal replacements for conventional fossil fuel energy sources. The development of highly active and electrochemically stable non-noble-metal electrocatalysts for the sluggish oxygen evolution reaction (OER) is considered to be an important step in decreasing the energy requirement during alkaline water electrolysis. Herein, we report a Sn-doped FeOx composite (SnFeOx) powder, which could be synthesized through a single-step hydrothermal method and is reported for the first time for OER during electrochemical water electrolysis. SnFeOx exhibits a low eta(100) (overpotential at 100 mA cm(-2) current density) value of 288 mV and a good Tafel slope of 35 mV dec(-1) in 1 M KOH, which surpasses the performance of standard non-PGM OER catalysts. A long-durability test at a higher current density of 100 mA cm(-2) for 50 h reveals the excellent activity retention of SnFeOx (>99%). The suitability of SnFeOx for full-water splitting was tested with Pt/C as a cathode electrode, and Pt/C/NF||SnFeOx/NF exhibited a lower eta(10) value of 1.56 V that is superior to Pt/C/NF||Ru/C/NF (1.59 V) with more than 99% retention at a current density of 10 mA cm(-2) for 50 h. The more favorable OER performance of SnFeOx compared to FeOx can be attributed to the successful Sn4+ doping along with increased oxygen defective sites and larger electrochemical surface area.

Foreign