Surface Reconstruction of LaSrCoFeO for Superimposed OER Performance.

Perovskites have become important OER electrocatalysts. Herein, as-prepared LaSrCoFeO (LSCF-0) is chosen as a sample to exhibit the superimposed effect of surface reconstruction accompanied by reduction of Co to Co on the further improvement of its activity and stability. As-synthesized LSCF-0 perovskite is chemically treated by simply immersing in an aqueous solution of NaBH for 1.0 h at room temperature. The optimized LSCF (LSCF-2) owns an amorphous layer consisting of nanosized particles of ∼20 nm (vs smooth bulk crystalline surface for untreated LSCF), which exhibits superior OER performance to LSCF-0. LSCF-2 has an overpotential of 248 mV (10 mA cm) and a Tafel slope of 51 mV dec (vs 355 mV and 76 mV dec for LSCF-0 and 381 mV and 91 mV dec for LCO) and an excellent cycle stability for 20 h running. This work supplies a new strategy to enhance OER performance through surface reconstruction of as-prepared perovskites.