Decorated and reconstructed perovskite-oxide electrodes for oxygen electrocatalysis and Zn-air batteries

Although decorated nanoparticles offer a great potential to generate extra active sites, their preparation usually requires time- and energy-consuming approaches. We report the remarkable activity and durability augmentation for the oxygen evolution reaction (OER) via effective and facile on-site electrochemical manipulation, using LaNiO₃ as a model catalyst. When compared to the pristine LaNiO₃, the electrochemically manipulated LaNiO₃ cycled in Fe³⁺-containing 0.1 M KOH (i.e., E-LNO+Fe) exhibits an almost three-fold improvement in current density at 1.65 V. It is experimentally and theoretically shown that the electrochemical manipulation leads to the creation of defective LaNiO_3-δ and NiO on the surfaces, which accelerate phase transformation to (oxy)hydroxides and hence the OER. Furthermore, a Zn-air battery assembled with E-LNO+Fe has demonstrated superior activity by presenting 171 mW cm^-2. Thus, our work demonstrates that substantial performance increases may be achieved by decorating and reconstructing perovskite-oxide electrodes via on-site electrochemical modification.