Co₃O₄ Nanowires Decorated with BO_x Species for Electrocatalytic Oxygen Evolution

One-dimensional nanowires possess significant advantages in active site exposure and electron and matter transport. Their oxygen evolution reaction (OER) performances can be well enhanced by the introduction of oxygen vacancies (Ov) and boron element (B), which, however, have not been achieved simultaneously. Herein, the Ov and BOx motifs were simultaneously employed in typical cobalt spinel oxide nanowires via simple NaBH4 hydrolysis (Co3O4/BOx). When grown on carbon fiber cloth, the observed Co3O4/BOx nanowire array electrode drives a current density of 10 mA cm–2 with only 328 mV overpotential in a 1.0 M KOH solution, which is much superior to the spinel Co3O4. We found that the BOx motifs and Ov have efficiently tuned electronic structures of Co3O4, thereby enhancing the electrical conductivity and generating a large number of electroactive sites. This study provides a simple solution for designing and producing nanostructure OER catalysts with excellent electrochemical performance.