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

Highlights: • The mutil-elemental perovskite oxides NFs with controllable tubular structure and morphology are synthesized by using electrospinning technology and Ostwald ripening approach. • The as-prepared perovskite oxides exhibits excellent OER activity due to the unique architecture of hollow NFs. • The LSCM-10 affords overpotential of 340 mV at current density of 10 mA cm⁻² and the Tafel slope is 111 mV dec⁻¹. 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_0.7Sr_0.3Co_0.25Mn_0.75O₃ nanofibers (LSCM NFs) consist of large amounts of building block La_0.7Sr_0.3Co_0.25Mn_0.75O₃ 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.