Honeycomb-like copper/cuprous oxide with supported nickel hydroxide layer as an electrode material for electrochemical oxidation of urea

Porous copper/cuprous oxide film composed of highly branched dendrites was grown around the individual wires of stainless steel (SS) woven mesh as a support for nickel hydroxide. The honeycomb-like copper/cuprous oxide film with an increased pore size from bottom to top was prepared using hydrogen bubbles as dynamic templates in cathodic deposition, which exhibited catalytic capability towards the electrochemical oxidation of urea (EOU). After electrodeposition of an ultrathin nickel hydroxide layer around the copper/cuprous oxide dendrites, the oxidation current density and onset potential of EOU could be much improved when compared to the bare dendritic copper/cuprous oxide electrode and nickel hydroxide-supported SS mesh. The enhanced catalytic performance could be attributed the three-dimensional porous copper/cuprous oxide film with supported nickel hydroxide layer that facilitated the transport of electron, electrolyte, and reactants and the release of gaseous products through the unique pore channels. (C) 2020 Elsevier B.V. All rights reserved.