Preparation of NiCuGO composite and investigation of its electrocatalytic properties in methanol oxidation

In this paper, an easy one-pot synthesis of an NiCuGO composite catalyst through electrodeposition is outlined. Various characterization techniques, such as SEM and XRD, were used for the characterization of the prepared catalyst. The catalyst's electrochemical activity was examined using cyclic voltammetry and chronoamperometry in 1 M KOH and 2 M MeOH / 1 M KOH solutions. The use of high current densities, 15.6 and 20.8 A dm⁻², allowed the preparation of powder coatings that after removal of the supporting material showed good electrocatalytic properties towards the methanol oxidation reaction (Ep_a 671 mV, ip_a 28.6 mA cm⁻², 33.7 mA mg⁻¹). For materials deposited with a higher current density, the presence of graphene oxide significantly increased their active surface (1.38 vs 1.04 mF cm⁻²). Such results suggest that electrodeposition can be a good alternative to “wet chemical” methods, such as hydrothermal process, that can require usage of toxic solvents, such as hydrazine for the preparation of catalysts for the direct methanol fuel cell (DMFC).