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 La 0.7 Sr 0.3 Co 0.25 Mn 0.75 O 3 nanofibers (LSCM NFs) consist of large amounts of building block La 0.7 Sr 0.3 Co 0.25 Mn 0.75 O 3 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 .