Integrating the cationic engineering and hollow structure engineering into perovskites oxides for efficient and stable electrocatalytic oxygen evolution

Abstract

Designing highly efficient oxygen evolution reaction (OER) electrocatalysts from nanoscale level has sparked great interest in several important catalytic reactions, such as water splitting, metal-air batteries, and regenerative fuel cells. Herein, we have reported an effective strategy for designing one-dimensional perovskite oxides with unique hollow nanostructures by combining an electrospinning technology and high temperature carbonization and oxidation. The LaCoO3 (LC) was used as the model catalyst and the La0.6Sr0.4CoO3 (LSC) and La0.6Sr0.4Co0.8Fe0.2O3 (LSCF) hollow nanofibers were synthesized through the A-site and AB-site doping engineering. The building block perovskite oxides nanoparticles connected with each other along one direction and formed a one-dimensional (1D) hollow nanofibers with hierarchical architectures. The one-dimensional perovskite oxide nanofibers can be tailored from porous hollow structures to solid nanofibers by adjusting the temperatures and the A, B site doping. Compared with the LC (444 mV) and the LSC (426 mV), the LSCF demonstrated the superior OER activity with overpotential of 353 mV (10 mA cm−2), suggesting the enhanced activity by the AB-site doping engineering. A series of LSCF electrocatalysts were prepared at different carbonization and oxidation conditions and the La0.6Sr0.4Co0.8Fe0.2O3 prepared at 700 °C obtained the best catalytic performance and exceptional durability. This strategy provides an effective approach to design advanced perovskite oxides catalysts with superior activity and stability.