Two-Phase Colloidal Synthesis of Amorphous Iron-Doped Manganese Phosphate Hollow Nanospheres for Efficient Water Oxidation

Exploitation of earth-abundant, efficient and stable electrocatalysts is of great significance for the oxygen evolution reaction (OER). Herein, a facile two-phase colloidal method is developed to synthesize amorphous iron-doped manganese phosphate (a-Fe-Mn:Pi) hollow nanospheres for the first time. Due to the synergistic interplay of hollow nanosphere morphology, amorphous structural character, and iron doping, the a-Fe-Mn:Pi catalyst possesses high electrochemically active surface area and excellent conductivity. As a consequence, the obtained a-Fe-Mn:Pi sample displays superior OER activity in alkaline condition with a small overpotential of 252 mV at 10 mA cm(-2) and a Tafel slope of 52.0 mV decade(-1) as well as 93.3% retention of the initial current density even after 20 h of reaction time. This work provides a new perspective on the design of hollow nanostructures for catalytic applications.