Highly Conductive\nNon-Calcined 2D Cu<sub>0.3</sub>Co<sub>0.7</sub> Bimetallic–Organic\nFramework for Urea Electrolysis\nin Simulated Seawater

Global\nclean energy demands can be effectively addressed\nusing\nthe promising approach of hydrogen energy generation combined with\nless energy consumption. Hydrogen can be generated, and urea-rich\nwastewater pollution can be mitigated in a low-energy manner using\nthe urea oxidation reaction (UOR). This paper seeks to assemble a\nunique electrocatalyst of a pristine 2D MOF, [Co(HBTC)(DMF)]<i><sub>n</sub></i> (Co-MUM-3), from 1,3,5-benzenetricarboxylate\n(BTC) to oxidize urea in simulated seawater. Ni foam (NF)-based working\nelectrodes were fabricated by incorporating a series of heterometallic\nCuCo-MUM-3 frameworks (Cu<sub>0.1</sub>Co<sub>0.9</sub>-MUM-3, Cu<sub>0.2</sub>Co<sub>0.8</sub>-MUM-3, Cu<sub>0.3</sub>Co<sub>0.7</sub>-MUM-3, and Cu<sub>0.4</sub>Co<sub>0.6</sub>-MUM-3), after which\ntheir application in the urea oxidation reaction was examined. A very\nlow required overpotential [1.26 V vs reversible hydrogen electrode\n(RHE) in 1 M KOH + 0.5 M NaCl (simulated seawater) + 0.33 M urea]\nand a Tafel slope of 112 mV dec<sup>–1</sup> could be observed\nfor the Cu<sub>0.3</sub>Co<sub>0.7</sub>-MUM-3 electrocatalyst, ensuring\nthe achievement of urea electro-oxidation and hydrogen evolution reactions\nat a corresponding 10 mA cm<sup>–2</sup> electrocatalytic current\ndensity. A relatively lower overpotential will be evident compared\nto other reported pristine MOFs, outperforming the commercial catalyst\nRuO<sub>2</sub> (1.41 V at 10 mA cm<sup>–2</sup>, 131 mV dec<sup>–1</sup>) and ensuring considerable stability at significantly\nhigh current densities for a minimum of 72 h.