Porous graphitic carbon microtubes derived from willow catkins as a substrate of MnO2 for supercapacitors

• Published in: Journal of power sources Vol. 344; pp. 176 - 184
• Main Authors: Zhang, Xiaohua, Zhang, Kang, Li, Hengxiang, Cao, Qing, Jin, Li'e, Li, Ping
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-03-2017
• Subjects: Carbon microtubes; Electrodeposition; Graphitization; Manganese oxide; Supercapacitor; Willow catkins; Willow catkins; Carbon microtubes; Supercapacitor; Electrodeposition; Manganese oxide; Graphitization
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2017.01.107

Biomass is receiving considerable attention because of its significant advantages as a sustainable and renewable material. Willow catkins, which have a single-walled microtubular structure are used as both a template and a precursor for synthesizing porous graphitic carbon microtubes (PGCMT) induced by the simultaneous activation–graphitization of K4Fe(CN)6. In addition to providing low-resistant pathways and short ion diffusion channels, as-obtained PGCMT with tubular structure also serves as an ideal platform for anchoring MnO2. The PGCMT/MnO2 composite electrode obtained by MnO2 electrodeposition expressed excellent electrochemical performance, including a significantly enhanced specific capacitance (550.8 F g−1 for the mass of MnO2 at a current density of 2 A g−1), a high capacitance retention of 61.8% even at a high current density of 50 A g−1, and an excellent cycling stability of 89.6% capability retention after 5000 cycles. These findings offer a simple and environmentally friendly strategy for preparing advanced energy materials by utilizing the unique structure of biomass waste from nature.
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•Willow catkins can be used as a template and a precursor for electrode materials.•K4Fe(CN)6 acts as both a graphitic catalyst precursor and an activating agent.•The PGCMT exhibits a high graphitic degree and a large specific surface area.•The PGCMT/MnO2 composites demonstrate excellent electrochemical properties.