Facile fabrication of exsolved nanoparticle-decorated hollow ferrite fibers as active electrocatalyst for oxygen evolution reaction

Hierarchical metal-oxide support catalysts for oxygen evolution reaction (OER) have attracted significant attention in the development of highly efficient and low-cost energy technology. However, the interaction between nanoparticles and perovskite supports is still unclear. Herein, we report a unique and simple strategy for enhancing OER activity based on ferrite (La0.9Fe0.92Ru0.08O3-δ, LFRO) nanofibrous architecture by in-situ growth of Ru/RuO2 nanoparticles. Hollow fibrous LFRO is synthesized by a modified electrospinning method. Ru and RuO2 nanoparticles anchor on the surface of LFRO substrate via a simple exsolution strategy. Benefiting from the synergic effect of the interaction of metal–metal oxides and large active surface area of hollow fibers, the nanofibrous LFRO electrode decorated by RuO2 nanoparticles delivers high electrocatalytic OER activity and durability. Meanwhile, KPFM measurement demonstrates that a low work function induced by plenty of oxygen vacancies could accelerate the charge transfer process and thus facilitate the OER kinetics. Our work provides insight into rational designing efficient hierarchical nanostructured electrocatalysts via a simplified in-situ growth method.