Efficient electrocatalyst of α-Fe 2 O 3 nanorings for oxygen evolution reaction in acidic conditions.

Large-scale application of sustainable energy devices urgently requires cost-effective electrocatalysts to overcome the sluggish kinetics related to the oxygen evolution reaction (OER) under acidic conditions. Here, we first report the highly efficient electrocatalytic characteristics of α-Fe 2 O 3 nanorings (NRs), which exhibits prominent OER electrocatalytic activity with lower overpotential of 1.43 V at 10 mA cm -2 and great stability in 1 M HCl, surpassing the start-of-the art Ir/C electrocatalyst. The significantly optimized OER activity of the α-Fe 2 O 3 NRs mainly attributes to the synergistic effect of the excellent electrical conductivity and a large effective active surface because of their unique nanoring structure, disordered surface, and the dynamic stability of α-Fe 2 O 3 NRs in acidic conditions.