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.