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 alpha-MnO2 nanorods to improve the water oxidation performance. The doping of Mo can transform the microstructure of alpha-MnO2 from nanorods into nanosphere superstructures. As a dopant, Mo expands the alpha-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/alpha-MnO2 is reduced by 80 mV (at 10 mA/cm2) compared with pure alpha-MnO2.