A novel graphite modified paper based cobalt-cobalt oxalate-nickel electrode for the electrooxidation of hydrogen peroxide

Abstract

The use of fossil energy has caused a serious burden on the environment, so it is urgent to find new and developable energy sources. H2O2 as a new type of clean fuel for fuel cell has received widespread attention. In this paper, a novel graphite modified paper based cobalt-cobalt oxalate-nickel ([email protected]–CoC2O4–Ni) electrode is fabricated by the simple “pencil depicting-electrodeposition-oxalic acid etching-electrodeposition” process for the electrooxidation of H2O2 in alkaline environment. The as-prepared [email protected]–CoC2O4–Ni electrode owns a novel and special three-dimensional (3D) porous structure, which can greatly increase the diffusion of reactants (NaOH and H2O2) during the electrochemical reaction process and lead a high catalytic activity for the electrooxidation of H2O2. More importantly, three main nanomaterial (Co, CoC2O4 and Ni) and some new generated substances during the CV test in NaOH solution (e.g. Ni(OH)2, NiOOH, Co(OH)2, CoOOH, Co3O4 and Co2O3 etc.) are on the surface of paper, which will enhance the electrocatalytic activity of the [email protected]–CoC2O4–Ni electrode to a great extent due to their synergistic effect. When the reaction solution contains 1.0 mol dm−3 NaOH and 0.2 mol dm−3 H2O2, the [email protected]–CoC2O4–Ni electrode exhibits a much higher oxidation current density (270.6 mA cm−2) than the FG, [email protected], [email protected], [email protected]–Ni and [email protected]–CoC2O4 electrodes. Besides, the whole preparation process for the [email protected]–CoC2O4–Ni electrode doesn't use any organic binder, ensuring the electrode owns good conductivity and stability for the electrochemical reaction. At last, the electrocatalytic mechanism for the electrooxidation of H2O2 is discussed. The Ni compounds and Co compounds are believed as the main catalytic substances, and the metallic Co core provides a fast route for the transfer of electrons. The super catalytic activity makes the prepared electrode in this study to be a promising material for the electrooxidation of H2O2 and the novel design idea gives some guidance for the fabrication of electrode materials in the field of fuel cell.