CIESC Journal ›› 2022, Vol. 73 ›› Issue (7): 3287-3297.DOI: 10.11949/0438-1157.20220391

• Material science and engineering, nanotechnology • Previous Articles    

Preparation of carbon nanotube bridged porous carbon by Ni/Co-ZIF-8 pyrolysis and its application to supercapacitors

Xue’an LIU(),Liyi TANG,Jian QIN,Dajiang TANG,Zhangfa TONG,Huiying QU()   

  1. Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, Guangxi, China
  • Received:2022-03-20 Revised:2022-05-15 Online:2022-08-01 Published:2022-07-05
  • Contact: Huiying QU

热解Ni/Co-ZIF-8制备碳纳米管桥连多孔碳及其在超级电容器中的应用

刘学安(),汤丽怡,覃健,唐大江,童张法,曲慧颖()   

  1. 广西大学化学化工学院,广西石化资源加工及过程强化技术重点实验室,广西 南宁 530004
  • 通讯作者: 曲慧颖
  • 作者简介:刘学安(1995—),男,硕士研究生,240208444@qq.com
  • 基金资助:
    国家自然科学基金项目(52002087);广西自然科学基金项目(2020GXNSFBA297002);广西科技计划项目(桂科AD20238064);广西石化资源加工及过程强化技术重点实验室主任基金项目(2021Z016)

Abstract:

Metal-organic frameworks (MOFs)-derived carbon materials have abundant pore structures and ultra-high specific surface areas, showing great potential in energy storage fields such as supercapacitors. Using environmental-friendly ZnO nanospheres (ZnO NS) as templates, the core-shell structured ZnO@Ni/Co-ZIF-8 precursor was prepared by hydrothermal method. The Ni, Co and N doped MOF-derived carbon materials Ni/Co-CN with different morphologies were obtained by pyrolysing ZnO@Ni/Co-ZIF-8 at different temperatures (700, 800, 900 and 950℃). The effect of the pyrolysis temperature on their energy storage performance was investigated. The results show that with the increase of the pyrolysis temperature, Ni/Co-CN gradually changes from porous carbon to carbon nanotube bridged porous carbon structure. When the pyrolysis temperature is 900℃, Ni/Co-CN-900 shows the highest specific capacitance. In the electrolyte of 1 mol/L KOH, the cyclic voltammetry curve remains a good symmetry, indicating superior electrochemical reversibility. By calculating the capacitance contribution and diffusion contribution ratios of charge storage in this process, it is found that the dominate capacitance contribution is due to the double-layer adsorption of porous carbon and a small amount originates from the Faradaic reaction caused by N doping. At a current density of 0.5 A/g, the specific capacitance of Ni/Co-CN-900 is up to 273.5 F/g. At the current density of 10.0 A/g, the specific capacitance still remains 93.8% after 5000 galvanostatic charge/discharge cycles, exhibiting excellent electrochemical performance.

Key words: metal-organic frameworks, supercapacitor, porous carbon, carbon nanotubes, core-shell structure

摘要:

金属-有机骨架(MOFs)衍生碳材料具有丰富的孔道结构和超高的比表面积,在超级电容器等储能领域展现出巨大潜力。以环保型ZnO纳米球为模板,通过水热法制备核壳结构ZnO@Ni/Co-ZIF-8前体。将其在四种温度(700、800、900、950℃)下热解,获得不同形貌的Ni、Co及N掺杂的MOFs衍生碳材料Ni/Co-CN,并探究了煅烧温度对其储能性能的影响。结果表明,随着煅烧温度升高,Ni/Co-CN逐渐由多孔碳变为碳纳米管桥连多孔碳结构。当热解温度为900℃时,Ni/Co-CN-900的比电容最大。在1 mol/L的KOH电解液中对其进行循环伏安测试,曲线对称性良好,表明其具有优异的电化学可逆性。通过计算该过程电荷存储的电容贡献和扩散贡献占比可知,Ni/Co-CN的储能主要来自多孔碳的双电层吸附,少量来自N掺杂导致的法拉第反应。在0.5 A/g的电流密度下,Ni/Co-CN-900的比电容高达273.5 F/g。在10.0 A/g的电流密度下进行5000次恒流充放电后,其比电容保持率高达93.8%,展现出良好的电化学性能。

关键词: 金属-有机骨架, 超级电容器, 多孔碳, 碳纳米管, 核-壳结构

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