Facile synthesis of FeCoW oxides: Effects of amorphous structure, electronic configuration and catalytic sites on water oxidation

Abstract

Catalysts with amorphous structures have shown excellent performance in electrocatalytic water oxidation, but it remains a challenge to prepare efficient catalysts using simple methods while maintaining high yields. Herein, amorphous FexCoyWz oxides nanoparticles were prepared by a one-step co-precipitation method, and the Fe content was optimized to ensure efficient water oxidation. The prepared Fe0.05Co0.09W0.61O0.25 had the best OER performance with a yield of 95.6% when the Co and Fe feeding ratio was 2:1. The Fe0.05Co0.09W0.61O0.25 possessed an overpotential of 267 mV at 10 mA cm−2 with a small Tafel slope of 39.4 mV dec−1. The activation energy at 1.5 V is only 49.4 kJ mol−1, and Faraday efficiency is close to 100%. The water oxidation performance of the two-electrode test shows that the voltages at 10 mA cm−2 are only 1.50 V. In addition, it still maintained high activity after 72 h of chronoamperometry test, which exhibits excellent water oxidation performance among similar non-precious transition metal catalysts. Therefore, the present work provides a simple and easy way to prepare high-activity and high-yield transition metal amorphous electrocatalysts.