Interface Engineering of Flower‐like Co 2 P/WO 3‐x /Carbon Cloth Catalysts with Oxygen Vacancies for Efficient Oxygen Evolution Reaction

Abstract The Constructing an efficient and low‐cost oxygen evolution reaction (OER) electrocatalyst is critical for improving the performance of electrolysis in alkaline water. In this study, a self‐supported electrocatalyst of flower‐like cobalt phosphide and tungsten oxide (Co 2 P/WO 3−x /CC) was prepared on carbon cloth (CC) surface by hydrothermal reaction with solution immersion etching and phosphorization annealing under H 2 /Ar atmosphere. This strategy can generate oxygen vacancies (O V ), improving the speed of charge transfer between cobalt phosphide (Co 2 P) and tungsten oxide (WO 3−x ) components. The catalyst greatly increases the electrochemical active surface area, which is beneficial for efficient oxygen evolution. Electrochemical testing studies show that in 1.0 M KOH solution, Co 2 P–WO 3−x /CC catalyst exhibits good OER activity, with a low overpotential of 254 mV at 10 mA cm −2 , a small Tafel slope of 58.32 mV dec −1 . The synergistic effect of oxygen vacancies and Co 2 P with WO 3−x can regulate electronic structures, expose more active sites, and cooperatively enhancing the OER activity. This study provides a workable strategy for preparing efficient non‐noble metal OER electrocatalysts on engineered interfaces and O V .