Building block nanoparticles engineering induces multi-element perovskite hollow nanofibers structure evolution to trigger enhanced oxygen evolution

Oxygen evolution reaction (OER) plays an important role in various renewable energy systems. Owing to its complex four-electron redox process, the OER process with sluggish kinetics often requires electrocatalysts to reduce the overpotential and promote the reaction rate. Herein, we have proposed an “all-in-one” strategy to synthesize mutil-elemental perovskite oxides nanofibers (NFs) with hollow and porous structures by using electrospinning technology and Ostwald ripening approach. The hollow La0.7Sr0.3Co0.25Mn0.75O3 nanofibers (LSCM NFs) consist of large amounts of building block La0.7Sr0.3Co0.25Mn0.75O3 nanoparticles (LSCM NPs), forming the unique architecture and the morphologies can be engineering by adjusting the calcination temperatures and the heating rates. Notably, the hollow LSCM NFs prepared at 800 °C and 10 °C min−1 demonstrated the excellent electrocatalytic performance, with overpotential of 340 mV at current density of 10 mA cm−2 and Tafel slope of 111 mV dec−1, as well as the long-term stability in alkaline electrolyte. The hollow NFs architectures exhibited a large specific surface area, a high porosity and a large inner space, which are beneficial for the OER, reducing the overpotentials and accelerating the electrode kinetics.