Composite Nanoarchitectonics of Co3O4 Nanopolyhedrons with N-Doped Carbon and Carbon Nanotubes for Alkaline Oxygen Evolution Reaction

Electrochemical water splitting is deemed to be an environmentally friendly methodology for hydrogen and oxygen in various electrochemical systems. The electrocatalyst has a strong relationship with the performance of the oxygen evolution reaction (OER). Herein, Co3O4 nanopolyhedrons (Co3O4 NPs) and Co3O4 nanopolyhedrons with N-doped carbon (Co3O4 NPs-NC) were obtained by changing the pyrolysis temperature using ZIF-67 as the precursor template. Due to the poor conductivity of cobalt-based oxides, the introduction of carbon nanotubes (CNTs) significantly increased the electron transfer rate of the Co3O4 polyhedron, the Co3O4 NPs-NC/CNTs exhibited outstanding activity as a catalyst in OER. The reason for the favorable catalytic capability of this catalyst is that the Co3O4 NPs-NC with dodecahedral structure can supply abundant active sites, and its plentiful mesoporous structure can facilitate the adsorption of reactants and desorption of products. Therefore, the Co3O4 NPs-NC/CNTs composite with excellent electrochemical activity has broad application prospects as a promising catalyst. The excellent OER performance of Co3O4 NPs-NC/CNTs is attributed to having a polyhedral structure that replicates the ZIF-67 morphology and its rich mesoporous structure, which can provide more effective active sites.