Exploring In Situ Kinetics of Oxygen Vacancy-Rich B/P-Incorporated Cobalt Oxide Nanowires for the Oxygen Evolution Reaction

Abstract

Defect-engineering of transition-metal oxide-based nanocatalysts is an innovative approach for improving the oxygen evolution reaction (OER) owing to their enhanced activity and stability. The present study introduces a facile approach aimed at enhancing OER activity by incorporating boron and phosphorus into cobalt oxide nanowires (B/P-CoO x NWs). The resulting material, enriched with oxygen vacancies (Ov), as confirmed by X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR), induced a complete structural transformation from Co3O4 to a CoO phase. The B/P-CoO x NWs exhibited an impressive overpotential of only 230 mV to achieve a current density of 10 mA cm–2 in 1 M KOH. The presence of Ov was proved to be responsible for the improvement in conductivity along with the quantity and quality of active sites. Electrochemical kinetic analysis was performed to reveal the crucial role of Ov in facilitating the OER mechanism by enhancing the adsorption and desorption of OH– ions and O2 molecules from the surface. The robustness of the developed electrocatalyst was demonstrated through a chronoamperometric test conducted over 80 h and a recyclability test spanning 10 000 cycles. This study focuses on the fabrication and dynamic investigation of the electrocatalyst, laying the groundwork for further advancements in non-noble material-based electrocatalysts.