Modulating Direct Growth of Copper Cobaltite Nanostructure on Copper Mesh as a Hierarchical Catalyst of Oxone Activation for Efficient Elimination of Azo Toxicant.

Abstract

As cobalt (Co) has been the most useful element for activating Oxone to generate SO₄^•-, this study aims to develop a hierarchical catalyst with nanoscale functionality and macroscale convenience by decorating nanoscale Co-based oxides on macroscale supports. Specifically, a facile protocol is proposed by utilizing Cu mesh itself as a Cu source for fabricating CuCo₂O₄ on Cu mesh. By changing the dosages of the Co precursor and carbamide, various nanostructures of CuCo₂O₄ grown on a Cu mesh can be afforded, including nanoscale needles, flowers, and sheets. Even though the Cu mesh itself can be also transformed to a Cu-Oxide mesh, the growth of CuCo₂O₄ on the Cu mesh significantly improves its physical, chemical, and electrochemical properties, making these CuCo₂O₄@Cu meshes much more superior catalysts for activating Oxone to degrade the Azo toxicant, Acid Red 27. More interestingly, the flower-like CuCo₂O₄@Cu mesh exhibits a higher specific surface area and more superior electrochemical performance, enabling the flower-like CuCo₂O₄@Cu mesh to show the highest catalytic activity for Oxone activation to degrade Acid Red 27. The flower-like CuCo₂O₄@Cu mesh also exhibits a much lower <i>E_a</i> of Acid Red 27 degradation than the reported catalysts. These results demonstrate that CuCo₂O₄@Cu meshes are advantageous heterogeneous catalysts for Oxone activation, and especially, the flower-like CuCo₂O₄@Cu mesh appears as the most effective CuCo₂O₄@Cu mesh to eliminate the toxic Acid Red 27.