Mo-Doped α-MnO₂ for Enhanced Electrocatalytic Water Oxidation

Manganese is a key metal involved in the catalysis of natural photosynthesis. Thus, the investigation of Mn-based electrocatalysts for water oxidation is of high importance. This work reports the doping of Mo into α-MnO₂ nanorods to improve the water oxidation performance. The doping of Mo can transform the microstructure of α-MnO₂ from nanorods into nanosphere superstructures. As a dopant, Mo expands the α-MnO₂ lattice to result in a decrease in the average oxidation state of Mn and the generation of oxygen vacancies, which are beneficial to water oxidation catalysis. Under optimized doping, the overpotential of 2.34 wt.% Mo/α-MnO₂ is reduced by 80 mV (at 10 mA/cm²) compared with pure α-MnO₂.