Mn and S dual-doping of MOF-derived Co3O4 electrode array increases the efficiency of electrocatalytic generation of oxygen

Owing to low-cost and 3d electronic configurations, Co3O4 material is considered as promising candidate for oxygen evolution reaction (OER) electrocatalyst, but the intrinsically low conductivity and limited active site exposure greatly limit the electrocatalytic performances, Herein, we successfully achieve modulation of Co3O4 arrays by Mn and S dual-doping for OER. Results demonstrate that Mn doping modifies the electronic structure of Co center to boost the intrinsic activity of active site in Co3O4, while inducing S in Co3O4 increases the electrical conductivity and provides ample S sites for proton adsorption. In addition, Mn and S dual-doping effectively increase the proportion of Co3+, resulting in facilitating the four-electron transfer and thus higher electrochemical activities. Consequently, the optimal Mn and S dual-doping Co3O4 presents low overpotentials of 330, 407 and 460 mV at 10, 100 and 300 mA cm−2 for OER, as well as a low Tafel slope of 68 mV dec−1 and a good durability after 20 h. Current work highlights a feasible strategy to design electrocatalysts via dual-doping and maximizing the high-valence transition metal ions.