Dual-anions engineering of bimetallic oxides as highly active electrocatalyst for boosted overall water splitting

Bimetallic oxides have unique advantages in driving both oxygen and hydrogen evolution reactions (OER/HER). Surface engineering of bimetallic oxides is a promising way to boost the catalytic activity by the regulation of electronic structure and surface property. Herein, a dual P, S-anions modification strategy is developed to optimize the catalytic performance of CoMoO₄ nanowire arrays. The formations of CoP and Co₃S₄ species on the CoMoO₄ surface bring heterojunction interfaces for more catalytic active sites and strong electronic interaction for faster interfacial charge transfer. Benefiting from these advantages, the P, S-CoMoO₄ catalyst on nickel foam (NF) delivers excellent catalytic activity and stability. The overpotentials at 10 mA cm^-2 of P, S-CoMoO₄/NF for HER are just 31 mV in acid media and 58 mV in alkaline media, respectively. In addition, by assembling the P, S-CoMoO₄/NF as bifunctional electrodes for overall water splitting, the electrolyzer exhibits a voltage of as low as 1.66 V at a current density of 50 mA cm^-2. This work put forward a new avenue for the development of advanced bifunctional electrocatalysts for water splitting.