Investigation of the synergistic effect on cobalt oxide modified silver surface for electrocatalytic hydrogen evolution reaction

Abstract Development of the nonprecious metal based catalysts for electrochemical hydrogen evolution reaction (HER) is of great industrial application in production of the clean energy carrier, hydrogen gas. In this work, Co3O4 catalysts with various morphologies were controllably fabricated via hydrothermal method by controlling the pH in precursors solutions and the particular Co3O4 catalyst obtained in the low pH range with ultrathin-sheet-aggregated-sphere structure performed catalytic output for HER. Then the Co3O4 catalysts were triggered into a higher active state with the equipment of Ag substrate. The overpotential at the HER current density of 10 mA cm−2 was optimized into −0.296 V and this catalytic enhancement is attributed to the heterohybrid synergism of spillover effect as well as the enlarged electrochemical specific area. This study turns the HER-inert Co3O4 into active and further provides a practical strategy to equip the Ag substrate for further enhancement of hydrogen evolution.