Facile synthesis of a ZnCo2O4 electrocatalyst with three-dimensional architecture for methanol oxidation

In this work, ZnCo2O4 nanomaterial with a hierarchical three-dimensional (3D) architecture is directly grown on Ni foam by a convenient solvothermal process and subsequent calcination treatment. The ZnCo2O4 hierarchical 3D architecture is constructed from coating a layer of ZnCo2O4 nanowires on ZnCo2O4 nanosheets. The growth mechanism of the ZnCo2O4 hierarchical 3D architecture is studied by control experiments. The as-prepared ZnCo2O4/Ni foam is applied as a binder-free electrode for the electrooxidation of methanol in KOH electrolyte. The electrocatalytic performances of the ZnCo2O4 electrodes prepared with different solvothermal reaction duration are studied, and the ZnCo2O4 electrode prepared with solvothermal reaction duration of 18 h shows the highest activity. The high electrocatalytic activity and excellent stability of the ZnCo2O4 relate to its hierarchical 3D architecture, porous nature, reversible redox characteristics and stability in alkaline electrolyte. (C) 2019 Elsevier B.V. All rights reserved.