Template-assisted construction of molybdenum-doped ruthenium dioxide hollow nanospheres for highly efficient acidic oxygen evolution reaction

Developing non-iridium-based electrocatalysts with enhanced activity and durability for acidic oxygen evolution reaction (OER) is urgently demanded for the overall efficiency of water electrolysis. In this study, a highly efficient Ti-supported Mo-doped RuO₂ hollow nanosphere electrocatalyst (Mo_x-RuO₂/Ti) is fabricated by a template-assisted method. The resulting Mo_0.25-RuO₂/Ti electrocatalyst with appropriate Mo doping demonstrates exceptional OER catalytic activity with a minimal overpotential of 175 mV at a current density of 10 mA cm⁻² and maintains a remarkable electrochemical stability of 400 h in acidic conditions, significantly superior to the commercial RuO₂/Ti catalyst. Based on the experimental results and theoretical calculations, this impressive OER performance stems from the synergistic effects of the high exposure of the active sites by the hollow spherical nanostructure and the electronic modulation of Ru active sites induced by Mo doping. This study underscores an effective approach for designing highly active and stable RuO₂-based electrocatalysts for acidic OER.