Zhang Xiangyu, Li Bin, Lan Minqiu, Yang Shengxiong, Xie Qianru, Xiao Junwu, Xiao Fei, Wang Shuai
Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, Department of Chemistry and Chemical Engineering, Huazhong University of Science & Technology, Wuhan 430074, P. R. China.
ACS Appl Mater Interfaces. 2021 Apr 28;13(16):18683-18692. doi: 10.1021/acsami.1c00579. Epub 2021 Apr 15.
Transition-metal sulfide is pursued for replacing scare platinum-group metals for oxygen electrocatalysis and is of great importance in developing low-cost, high-performance rechargeable metal-air batteries. We report herein a facile cationic-doping strategy for preparing nickel-doped cobalt sulfide embedded into a mesopore-rich hydrangea-like carbon nanoflower. Nickel cations are introduced to induce the formation of Co-active species and more oxygen vacancies due to higher electronegativity and smaller ionic radius, thereby strengthening the intrinsic activity for oxygen electrocatalysis. Moreover, hydrangea-like superstructure composed of interconnected carbon cages provides abundant accessible active sites and hierarchical porosity. As a result, it shows excellent catalytic performance with a superior mass activity for the oxygen reduction reaction to the state-of-the-art Pt/C catalyst and a low overpotential of 314 mV at 10 mA cm for the oxygen evolution reaction. When used as an air cathode for the rechargeable Zn-air battery, it delivers a peak power density of 96.3 mW cm and stably operates over 214 h. This work highlights the importance of cationic doping in strengthening the electrocatalytic performance of 3d-transition-metal chalcogenides.
过渡金属硫化物有望替代稀缺的铂族金属用于氧电催化，并且在开发低成本、高性能的可充电金属空气电池方面具有重要意义。我们在此报告一种简便的阳离子掺杂策略，用于制备嵌入富含介孔的绣球花状碳纳米花中的镍掺杂硫化钴。由于镍阳离子具有更高的电负性和更小的离子半径，引入镍阳离子可诱导形成钴活性物种和更多氧空位，从而增强氧电催化的本征活性。此外，由相互连接的碳笼组成的绣球花状超结构提供了丰富的可及活性位点和分级孔隙率。结果，它表现出优异的催化性能，对于氧还原反应，其质量活性优于目前最先进的Pt/C催化剂，对于析氧反应，在10 mA cm时过电位低至314 mV。当用作可充电锌空气电池的空气阴极时，它的峰值功率密度为96.3 mW cm，并且能稳定运行超过214小时。这项工作突出了阳离子掺杂在增强3d过渡金属硫族化合物电催化性能方面的重要性。
