Wang Yunpeng, Qian Guangfu, Yu Hui, Xie Zehan, Li Liancen, Lu Minsheng, Chen Changzhou, Min Douyong, Chen Jinli, Tsiakaras Panagiotis
College of Light Industry and Food Engineering, Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Guangxi University, Nanning, 530004, China.
State Key Laboratory of Materials Processing & Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
Small. 2025 Feb;21(5):e2410044. doi: 10.1002/smll.202410044. Epub 2024 Dec 18.
Developing highly efficient biomass-derived carbon-based electrocatalysts remains challenging for urea electrolysis because most of these electrocatalysts show powder morphology, which can lead to Ostwald ripening during the reaction process, and its reaction mechanism should be further verified. Herein, self-supported lignin-derived carbon coupling NiO@MoNi heterojunction (NiO@MoNi/C) possesses superhydrophilic properties and electronic modulation, boosting the performance of urea electrolysis. Electrochemical results show that an indirect oxidation step for urea oxidation reaction (UOR) and Volmer-Heyrovsky mechanism for hydrogen evolution reaction (HER) occurs on the surface of NiO@MoNi/C. It displays low potentials for UOR (E = 1.28/1.41/1.47 V) and for HER (E = -38/-264/-355 mV) in 1.0 M KOH + 0.5 M urea electrolyte solution. The good activity is ascribed to the self-supported lignin-derived carbon and heterojunction, which increases the number of active sites, optimizes electronic structure, and improves electron transfer. Benefiting from the self-supported lignin-derived carbon, NiO@MoNi/C demonstrates corrosion resistance and superhydrophilicity, which avoids Ostwald ripening and accelerates gas-liquid transfer, thus, maintaining for 100 h at ±1000/±1500 mA cm during the UOR and HER test. This work provides a good catalyst for urea electrolysis and presents a promising way for preparing lignin-derived carbon-based catalysts while expanding the application of lignin-based biomass carbon materials.
开发高效的生物质衍生碳基电催化剂用于尿素电解仍然具有挑战性，因为这些电催化剂大多呈现粉末形态，这可能导致反应过程中的奥斯特瓦尔德熟化，并且其反应机理仍需进一步验证。在此，自支撑木质素衍生碳耦合NiO@MoNi异质结（NiO@MoNi/C）具有超亲水性和电子调制特性，提升了尿素电解性能。电化学结果表明，尿素氧化反应（UOR）的间接氧化步骤和析氢反应（HER）的Volmer-Heyrovsky机理发生在NiO@MoNi/C表面。在1.0 M KOH + 0.5 M尿素电解质溶液中，它对UOR显示出低电位（E = 1.28/1.41/1.47 V），对HER显示出低电位（E = -38/-264/-355 mV）。良好的活性归因于自支撑木质素衍生碳和异质结，它们增加了活性位点数量，优化了电子结构，并改善了电子转移。受益于自支撑木质素衍生碳，NiO@MoNi/C表现出耐腐蚀性和超亲水性，避免了奥斯特瓦尔德熟化并加速了气液转移，因此，在UOR和HER测试期间，在±1000/±1500 mA cm下可保持100小时。这项工作为尿素电解提供了一种优良的催化剂，并为制备木质素衍生碳基催化剂提供了一条有前景的途径，同时拓展了木质素基生物质碳材料的应用。
