Li Yingjie, Huang Bolong, Sun Yingjun, Luo Mingchuan, Yang Yong, Qin Yingnan, Wang Lei, Li Chunji, Lv Fan, Zhang Weiyu, Guo Shaojun
Department of Materials Science and Engineering College of Engineering, Peking University, Beijing, 100081, China.
Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, 999077, Hong Kong SAR, China.
Small. 2019 Jan;15(1):e1804212. doi: 10.1002/smll.201804212. Epub 2018 Dec 5.
The development of cost-efficient, active, and stable electrode materials as bifunctional catalysts for electrochemical water splitting is crucial to high-performance renewable energy storage and conversion devices. In this work, the synthesis of Co-based multi-metal borides nanochains with amorphous structure is reported for boosting the oxygen evolution (OER) and hydrogen evolution reactions (HER) by one-pot NaBH reduction of Co , Ni , and Fe under ambient temperature. In all the investigated Co-based metal borides, NiCoFeB nanochains show the excellent OER performance with a low overpotential of 284 mV at 10 mA cm and Tafel slope of 46 mV dec , respectively, together with excellent catalytic stability, and robust HER performance with an overpotential of 345 mV at 10 mA cm . The density functional theory (DFT) calculations reveal that the excellent electrocatalytic performance is mainly attributed to optimal electronic structure by tuning the Co-3d band activities by the incorporation of Ni and Fe for enhanced water splitting via the potentially existed Co state. Moreover, the electrolyzer using NiCoFeB nanochains as anode and cathode offers 10 mA cm at a cell voltage of 1.81 V, comparable to commercial Pt/C // Ir/C, providing a simple method to design and explore highly efficient and cheap bifunctional electrocatalysts for overall water splitting.
开发具有成本效益、活性和稳定性的电极材料作为电化学水分解的双功能催化剂，对于高性能可再生能源存储和转换装置至关重要。在这项工作中，报道了通过在室温下用NaBH一锅还原Co、Ni和Fe来合成具有非晶结构的Co基多金属硼化物纳米链，以促进析氧反应（OER）和析氢反应（HER）。在所有研究的Co基金属硼化物中，NiCoFeB纳米链表现出优异的OER性能，在10 mA cm时过电位低至284 mV，塔菲尔斜率为46 mV dec，同时具有出色的催化稳定性，以及在10 mA cm时过电位为345 mV的稳健HER性能。密度泛函理论（DFT）计算表明，优异的电催化性能主要归因于通过掺入Ni和Fe来调节Co-3d能带活性，从而优化电子结构，通过潜在存在的Co状态增强水分解。此外，使用NiCoFeB纳米链作为阳极和阴极的电解槽在1.81 V的电池电压下提供10 mA cm，与商业Pt/C // Ir/C相当，为设计和探索用于整体水分解的高效廉价双功能电催化剂提供了一种简单方法。
