Trace F-doped Co3O4 nanoneedles for enhanced acidic water oxidation activity via promoting OH coverage

Abstract

Exploring Earth-abundant and efficient electrocatalysts to replace Ir and Ru for the acidic oxygen evolution reaction (OER) is essential to reduce the cost of clean hydrogen production. Here, we show that trace amounts of electronegative non-metallic element fluorine (F)-doped Co₃O₄ nanoneedles improve the activity and stability of Co₃O₄. The F-doped Co₃O₄ nanoneedles supported on carbon paper (F-Co₃O₄/CP) exhibit an overpotential of 350 mV at 10 mA cm⁻² for the acidic OER. In addition, their performance remains consistent after continuous operation for 80 h. Detailed investigations reveal that introducing an anion promotes the enrichment of OH on the surface of Co₃O₄ and prevents acid corrosion, thereby enhancing the intrinsic OER activity and stability. Theoretical calculations further indicate that F doping can effectively improve electron transfer and optimize the energy barrier for the formation of *OOH intermediates, which significantly improves OER performance. This study provides guidance for designing efficient and stable non-noble metal acidic water oxidation catalysts.