Ding Qian, Yin Jia, Huang Yueyue, Wang Chaofan, Luo Hubin, Sun Shiguo, Xu Yongqian, Li Hongjuan
Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Xinong Road 22, Yangling, Shaanxi 712100, PR China.
Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, PR China; CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, PR China.
J Colloid Interface Sci. 2024 Jun 15;664:263-274. doi: 10.1016/j.jcis.2024.03.044. Epub 2024 Mar 8.
In recent years, ternary layered double hydroxide (LDH) has become a research hotspot for electrode materials and oxygen evolution reaction (OER) catalyst due to the enhanced synergistic effect between individual elements. However, the application of LDH is greatly limited by its low electrical conductivity and the disadvantage that nanosheets tend to accumulate and mask the active sites. Herein, a novel Ru-doped CoNiFe - LDH was prepared via a facile hydrothermal method. According to the density functional theory (DFT) calculations, the doping of Ru element could improve electron state density and band gaps of LDH and consequently boosted the electrochemical reaction kinetics as well as electrical conductivity. Furthermore, introduction of Ru atom induced the formation of porous flower-like structures in nanosheets. Compared to CoNiFe - LDH (28.9 m/g), Ru-doped CoNiFe - LDH performed larger specific surface area of 53.1 m/g, resulting in more electrochemically active sites. In these case, Ru-doped CoNiFe - LDH demonstrated better energy storage performance of 176.0 mAh/g at 1 A/g compared to original CoNiFe - LDH (78.9 mAh/g at 1 A/g). Besides, the assembled Ru-doped CoNiFe - LDH//activated carbon (AC) device delivered a maximum energy density of 36.4 W h kg at the power density of 740.3 W kg and an outstanding cycle life (78.7 % after 10,000 cycles). Meanwhile, Ru-doped CoNiFe - LDH exhibited lower overpotential (339 mV at 50 mA cm) and Tafel slope (93.2 mV dec). Therefore, this work provided novel and valuable insights into the rational doping of Ru elements for the controlled synthesis of supercapacitor electrode materials and OER catalysts.
近年来，由于各元素之间增强的协同效应，三元层状双氢氧化物（LDH）已成为电极材料和析氧反应（OER）催化剂的研究热点。然而，LDH的应用受到其低电导率以及纳米片易于聚集并掩盖活性位点这一缺点的极大限制。在此，通过简便的水热法制备了一种新型的Ru掺杂CoNiFe-LDH。根据密度泛函理论（DFT）计算，Ru元素的掺杂可以改善LDH的电子态密度和带隙，从而提高电化学反应动力学以及电导率。此外，Ru原子的引入诱导了纳米片中多孔花状结构的形成。与CoNiFe-LDH（28.9 m²/g）相比，Ru掺杂的CoNiFe-LDH具有更大的比表面积，为53.1 m²/g，从而产生更多的电化学活性位点。在这种情况下，与原始的CoNiFe-LDH（1 A/g时为78.9 mAh/g）相比，Ru掺杂的CoNiFe-LDH在1 A/g时表现出更好的储能性能，为176.0 mAh/g。此外，组装的Ru掺杂CoNiFe-LDH//活性炭（AC）器件在功率密度为740.3 W/kg时提供了36.4 W h/kg的最大能量密度以及出色的循环寿命（10000次循环后为78.7%）。同时，Ru掺杂的CoNiFe-LDH表现出更低的过电位（50 mA/cm²时为339 mV）和塔菲尔斜率（93.2 mV/dec）。因此，这项工作为合理掺杂Ru元素以可控合成超级电容器电极材料和OER催化剂提供了新颖且有价值的见解。
