Superhydrophilic CoMoO4 with high oxygen vacancy for outstanding alkaline OER

The development of low-cost, long-life alkaline OER catalysts with competitive precious metal activity is of great importance for the sustainable decomposition of water and the development of hydrogen energy. In this study, Mo-doped CoOx electrode CMOT (Co: Mo = 7:3+Tween20) with superhydrophilic surface structure was prepared on titanium plates by using a more industrial thermal decomposition coating method. The results showed that the addition of Mo not only adjusted the pore structure of the catalyst but also increased the oxygen vacancy level. The self-loading effect of Tween20 makes the catalyst more dispersed and granulated. It changes the particle size distribution and improves the specific surface area while increasing the wettability of the material surface and accelerating the adsorption of water molecules at the anode. When the electrode is used for anodic oxygen evolution, its oxygen evolution overpotential at 0.1 M KOH, 10 mA cm−2 is as low as 250 mV vs.RHE. Its accelerated life can be up to 304 h under severe test conditions of 1 M KOH, 1 A cm−2, 60 °C. Therefore, the CMOT electrode has excellent OER catalytic activity and stability. This study provides a new idea for developing anode materials for water electrolysis hydrogen production.