Acid etching driven regulation of surface defects in perovskite oxides for superior OER performance

Acid-etching strategy unlocks electrocatalytic potential of perovskite oxides. • H-LBO achieves a low overpotential of 213 mV at 10 mA cm - 2 . • Optimized electronic structure and oxygen vacancies boost OER activity. To advance sustainable hydrogen production, we developed an acid-etching strategy to enhance perovskite oxides for oxygen evolution reaction (OER). This method preferentially removes A-site cations (La, Sr), accompanied by slight Ni loss, inducing A-site deficiency and oxygen vacancy while exposing B-site centers. The etched perovskite oxide (H-LBO) achieves superior OER activity with a low overpotential of 213 mV at 10 mA cm - 2 in 1 M KOH, outperforming pristine perovskite oxide (LBO, 285 mV) and commercial RuO 2 (389 mV). This work offers a simple approach to modulate surface defects and electronic structures for cost-effective, high-performance OER electrocatalysts. Download: Download high-res image (205KB) Download: Download full-size image