An efficient 3D ordered mesoporous Cu sphere array electrocatalyst for carbon dioxide electrochemical reduction

The electrochemical reduction of CO2 is a promising solution for sustainable energy research and carbon emissions. However, this solution has been challenged by the lack of active and selective catalysts. Here, we report a two-step synthesis of 3D ordered mesoporous Cu sphere arrays, which is fabricated by a dual template method using a poly methyl methacrylate (PMMA) inverse opal and the nonionic surfactant Brij 58 to template the mesostructure within the regular voids of a colloidal crystal. Therefore, the well-ordered 3D interconnected bi-continuous mesopores structure has advantages of abundant exposed catalytically active sites, efficient mass transport, and high electrical conductivity, which result in excellent electrocatalytic CO2 RR performance. The prepared 3D ordered mesoporous Cu sphere array (3D-OMCuSA) exhibits a low onset potential of -0.4 V at a 1 mA cm(-2) electrode current density, a low Tafel slope of 109.6 mV per decade and a long-term durability in 0.1 M potassium bicarbonate. These distinct features of 3D-OMCuSA render it a promising method for the further development of advanced electrocatalytic materials for CO2 reduction. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.