CuO-Ni(OH)2 nanosheets as effective electro-catalysts for urea oxidation

• The cost of Cu 2 O is low, and its shape and structure are controllable. • Support CuO can effectively promote the activity of catalyst Ni(OH) 2 . • CuO-Ni(OH) 2 -d has excellent UOR properties owning to the nanosheets morphologies. • The electrocatalyst showed negligible degradation during 36 h electrolysis of urea. The electrooxidation of urea is identified as a prospective route for the degradation of urea-rich wastewater and hydrogen generation. Here, we report a controllable synthetic strategy to develop CuO-Ni(OH) 2 -d nanosheets by deliberately selecting S 2 O 3 2− as the coordinating etchant toward to Cu 2 O template and optimize the reaction conditions. The CuO-Ni(OH) 2 -d is composed of CuO quadrangle nanosheets (100–200 nm) dispersed with Ni(OH) 2 nanoparticles. As predicted, The CuO-Ni(OH) 2 -d nanosheets catalysts exhibit high UOR activities at 1.41 V vs. RHE to achieve the current density of 10 mA cm −2 under the condition of 1 M KOH with 0.33 M urea. The CuO-Ni(OH) 2 -d nanosheets catalyst also emerges a higher current density of 21.5 mA cm −2 , which is about 5.3, 6.8, 30, and 2 times larger than those of commercial Ni(OH) 2 , CuO-Ni(OH) 2 -a, CuO-Ni(OH) 2 -b and CuO-Ni(OH) 2 -c at 1.52 V vs. RHE, respectively. In particular, the CuO-Ni(OH) 2 -d nanosheets catalysts exhibited the best catalytic stability performance. After the 36 h I-T test, the current density has no noticeable decreasing compared with the initial current density. This work could present a strategy for the design of advanced electrode materials that can be further applied in urea-rich wastewater remediation.