Tahir M Usman, Arshad Hina, Zhang Heng, Hou Zhiyan, Wang Jide, Yang Chao, Su Xintai
Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control, Guangdong University of Petrochemical Technology, Maoming 525000, PR China; Ministry Key Laboratory of Oil and Gas Fine Chemicals, College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, PR China; School of Chemical Engineering, The University of Faisalabad, Faisalabad 37610, Pakistan.
Ministry Key Laboratory of Oil and Gas Fine Chemicals, College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, PR China.
J Colloid Interface Sci. 2020 Nov 1;579:195-204. doi: 10.1016/j.jcis.2020.06.050. Epub 2020 Jun 12.
Single imidazolate framework-67 (ZIF-67) is commonly used as a template to prepare layered double hydroxides (LDHs) with specific morphology to improve the performance of materials. Herein, the Co ion in ZIF-67 is partially substituted by Ni to obtain the dodecahedron bimetallic imidazolate framework (CoNi-ZIF). Subsequently, using bimetallic CoNi-ZIF as the sacrificial template, CoNi-LDH hierarchical hollow cage structures with wrinkled nanosheet arrays are synthesized at room temperature and in aqueous solution by an inexpensive and environment friendly surfactant-free approach. The optimized etched CoNi-LDH4 has a maximum specific capacitance of 1877 F g at a current density of 1 A g, and cycling stability of 99.89% after 5000 cycles, which is significantly better than that of ZIF-67 derived CoNi-LDH67 (1357 F g at 1 A g, cycling stability of 73.35%). The asymmetric supercapacitor with CoNi-LDH4 as a cathode and activated carbon (AC) as anode has an energy density of 49.3 Wh kg at 750 W kg power output and stable cycling performance (capacity retention of 92.13% after 5000 cycles). This study shows the prospect of bimetallic CoNi-ZIF derived LDHs nanostructures prepared at room temperature and in aqueous solution to improve the performance and stability of supercapacitors.
单一咪唑框架-67（ZIF-67）通常用作模板来制备具有特定形态的层状双氢氧化物（LDH），以提高材料性能。在此，ZIF-67中的Co离子被Ni部分取代，得到十二面体双金属咪唑框架（CoNi-ZIF）。随后，以双金属CoNi-ZIF为牺牲模板，通过一种廉价且环境友好的无表面活性剂方法，在室温和水溶液中合成了具有皱纹纳米片阵列的CoNi-LDH分级中空笼状结构。优化后的蚀刻CoNi-LDH4在电流密度为1 A g时具有1877 F g的最大比电容，在5000次循环后循环稳定性为99.89%，明显优于ZIF-67衍生的CoNi-LDH67（在1 A g时为1357 F g，循环稳定性为73.35%）。以CoNi-LDH4为阴极、活性炭（AC）为阳极的不对称超级电容器在750 W kg功率输出下的能量密度为49.3 Wh kg，具有稳定的循环性能（5000次循环后容量保持率为92.13%）。本研究展示了在室温和水溶液中制备的双金属CoNi-ZIF衍生的LDH纳米结构在提高超级电容器性能和稳定性方面的前景。
