Enhanced Electrocatalytic Oxygen Evolution by Manipulation of Electron Transfer through Cobalt-Phosphorous Bridging

Abstract Bridging heteroatoms on the surface of electrocatalysts, aiming to modify the surface atomic and electronic configuration, is of prime importance to improve the electrocatalytic performance. The present work establishes Co-P bridging on the surface of Co3O4 via a vapor-assisted treatment in a controlled molar ratio of P/Co (0.08 ∼ 0.66). The oxygen evolution reaction (OER) activity of P/Co3O4 showed a compositional dependence, reaching the optimal performance with a low overpotential of 314 mV for achieving a current density of 10 mA cm-2. Both experimental characterization and density functional theory calculations indicate that the improved OER performance derives from the establishment of Co-P bridging. The bridging creates more Co2+ ions and oxygen vacancies by driving electrons transfer between P and Co, and thus results in the creation of more active sites, improvement of intrinsic activity, enhancement of electrical conductivity and improvement of electrochemical stability. Furthermore, the present work demonstrates that this generic synthetic approach can also be applied to improve HER and overall water splitting with higher electrochemical activity.