Tan Haojie, Zhang Yifan, Geng Ying, Li Hui, Bi Siyu, Xia Zhengqiang, Yang Qi, Wei Qing, Chen Sanping
Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, China.
Shaanxi Key Laboratory for Carbon Neutral Technology, Carbon Neutrality College (Yulin), Northwest University, Xi'an 710069, China.
Inorg Chem. 2024 Jul 22;63(29):13484-13494. doi: 10.1021/acs.inorgchem.4c01581. Epub 2024 Jul 11.
Transition metal phosphide/sulfide (TMP/TMS) heterostructures are attractive supercapacitor electrode materials due to their rapid redox reaction kinetics. However, the limited active sites and weak interfacial interactions result in undesirable electrochemical performance. Herein, based on constructing the NiCo-LDH template on Ni-MOF-derived NiP/NC, NiP/NC@CoNiS with a porous heterostructure is fabricated by sulfurizing the intermediate and is used for supercapacitors. The exposed Ni sites in the phosphating-obtained NiP/NC coordinate with OH to form an intimate-connected NiP/NC@NiCo-LDH, and the CoNiS nanosheets retaining the original cross-linked structure of NiCo-LDH integrate the porous carbon skeleton of NiP/NC to yield a hierarchical pore structure with rich electroactive sites. The conducting carbon backbone and the intense electronic interactions at the interface accelerate electron transfer, and the hierarchical pores offer sufficient ion diffusion paths to accelerate redox reactions. These confer NiP/NC@CoNiS with a high specific capacitance of 2499 F·g at 1 A·g. The NiCo-LDH template producing a tight interfacial connection, significantly enhances the stability of the heterostructure, leading to a 91.89% capacitance retention after 10,000 cycles. Moreover, the fabricated NiP/NC@CoNiS//NC asymmetric supercapacitor exhibits an excellent energy density of 73.68 Wh kg at a power density of 700 W kg, superior to most reported composites of TMPs or TMSs.
过渡金属磷化物/硫化物（TMP/TMS）异质结构因其快速的氧化还原反应动力学而成为有吸引力的超级电容器电极材料。然而，有限的活性位点和较弱的界面相互作用导致其电化学性能不理想。在此，基于在镍基金属有机框架衍生的NiP/NC上构建NiCo-LDH模板，通过对中间体进行硫化制备了具有多孔异质结构的NiP/NC@CoNiS，并将其用于超级电容器。磷化得到的NiP/NC中暴露的Ni位点与OH配位形成紧密连接的NiP/NC@NiCo-LDH，保留NiCo-LDH原始交联结构的CoNiS纳米片与NiP/NC的多孔碳骨架整合，形成具有丰富电活性位点的分级孔结构。导电的碳骨架和界面处强烈的电子相互作用加速了电子转移，分级孔提供了足够的离子扩散路径以加速氧化还原反应。这些赋予NiP/NC@CoNiS在1 A·g时2499 F·g的高比电容。产生紧密界面连接的NiCo-LDH模板显著提高了异质结构的稳定性，在10000次循环后电容保持率为91.89%。此外，制备的NiP/NC@CoNiS//NC不对称超级电容器在功率密度为700 W kg时表现出73.68 Wh kg的优异能量密度，优于大多数报道的TMP或TMS复合材料。
