Water electrolysis has become a promising green and sustainable strategy for hydrogen fuel production. However, due to the slow kinetics of the oxygen evolution reaction (OER), large overpotentials are required to drive the overall reaction. In this work, we demonstrate an environmentally friendly and energy-saving strategy by the synergy of the urea oxidation reaction (UOR) with the hydrogen evolution reaction (HER) to replace the ordinary water hydrolysis. In order to further boost the UOR kinetics, nickel borate (Ni–B_i) is synthesized by a facile co-precipitation method, forming a nanosheet morphology and 3D hierarchical porous structure. The resulting Ni–B_i catalyst exhibits exceptionally high catalytic performance for the UOR, achieving a current density of 50 mA cm⁻² at 1.42 V vs. RHE, which is about 250 mV lower than that of the OER process. The two-electrode urea electrolytic cell composed of the Ni–B_i anode and a Pt cathode requires a small cell voltage of 1.66 V in order to reach a current density of 50 mA cm⁻² and is very stable. Overall, this work demonstrates a promising electrocatalyst system for efficient hydrogen production and simultaneous urea-containing wastewater treatment, providing valuable information for the development of advanced non-noble metal catalysts for the UOR.

中文翻译：

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具有3D分层结构的硼酸镍作为尿素氧化的强大而有效的电催化剂

水电解已成为氢燃料生产的一种有前途的绿色可持续战略。但是，由于氧气释放反应（OER）的动力学缓慢，需要大的超电势来驱动整个反应。在这项工作中，我们通过尿素氧化反应（UOR）与析氢反应（HER）的协同作用演示了一种环保和节能的策略，以取代普通的水水解反应。为了进一步提高UOR动力学，通过简便的共沉淀法合成了硼酸镍（Ni-B _i），形成了纳米片形态和3D分层多孔结构。将所得的Ni-B_我为UOR催化剂表现出非常高的催化性能，实现为50mA cm 2的电流密度相对于RHE，在1.42 V时为⁻²，比OER工艺低约250 mV。由Ni-B _i阳极和Pt阴极组成的两电极尿素电解池需要1.66 V的小池电压，才能达到50 mA cm ^-2的电流密度，并且非常稳定。总体而言，这项工作展示了一种有前途的电催化剂系统，可有效制氢并同时处理含尿素的废水，为开发用于UOR的高级非贵金属催化剂提供了有价值的信息。