Wang Chao, Wang Qirun, Du Xiaoqiang, Zhang Xiaoshuang
School of Chemistry and Chemical Engineering, Shanxi Key Laboratory of High Performance Battery Materials and Devices, North University of China, Xueyuan road 3, Taiyuan 030051, People's Republic of China.
School of Environment and Safety Engineering, North University of China, Xueyuan road 3, Taiyuan 030051, People's Republic of China.
Dalton Trans. 2023 Sep 26;52(37):13161-13168. doi: 10.1039/d3dt02586a.
Urea electrolysis can be used to treat wastewater containing urea and alleviate the energy crisis, so it is one of the best ways to solve environmental and energy problems. This paper reports the synthesis of M doped NiVS (M = Co, Ce and Cr) composites by a simple hydrothermal process for the first time. What is noteworthy is that the Ce-NiVS material as a catalytic electrode requires only 141 mV overpotential for the hydrogen evolution reaction (HER) and 1.291 V potential for the urea oxidation reaction (UOR) at a current density of 10 mA cm in 1.0 M KOH and 0.5 M urea mixed alkaline solution. Using Ce-NiVS/NF as both the anode and cathode for urea electrolysis, a current density of 10 mA cm is driven by a voltage of only 1.55 V, which is better than most previous catalysts. Experimental results demonstrate that the excellent catalytic activity of Ce-NiVS materials is due to the formation of a large number of active sites and the improvement of conductivity due to doping with Ce. Density functional theory calculation shows that the VS material has a small Gibbs free energy of hydrogen adsorption, which plays a major role in the hydrogen production process, and Ce-NiS has a higher density of states (DOS) near the Fermi level, indicating that Ce-NiS has better electronic conductivity. The synergistic catalysis of VS and Ce-NiS promoted the hydrogen production performance of the Ce-NiVS material. This work provides guidance for the optimization and design of low-cost electrocatalysts to replace expensive precious metal-based electrocatalysts for overall urea electrolysis.
尿素电解可用于处理含尿素的废水并缓解能源危机，因此它是解决环境和能源问题的最佳方法之一。本文首次报道了通过简单水热法合成M掺杂的NiVS（M = Co、Ce和Cr）复合材料。值得注意的是，在1.0 M KOH和0.5 M尿素的混合碱性溶液中，Ce-NiVS材料作为催化电极，在电流密度为10 mA cm时，析氢反应（HER）的过电位仅为141 mV，尿素氧化反应（UOR）的电位为1.291 V。使用Ce-NiVS/NF作为尿素电解的阳极和阴极，仅需1.55 V的电压就能驱动10 mA cm的电流密度，这比大多数先前的催化剂都要好。实验结果表明，Ce-NiVS材料优异的催化活性归因于大量活性位点的形成以及Ce掺杂导致的电导率提高。密度泛函理论计算表明，VS材料具有较小的氢吸附吉布斯自由能，这在产氢过程中起主要作用，而Ce-NiS在费米能级附近具有更高的态密度（DOS），表明Ce-NiS具有更好的电子导电性。VS和Ce-NiS的协同催化促进了Ce-NiVS材料的产氢性能。这项工作为优化和设计低成本电催化剂提供了指导，以替代用于整体尿素电解的昂贵的贵金属基电催化剂。
