Bamboo-like, oxygen-doped carbon tubes with hierarchical pore structure derived from polymer tubes for supercapacitor applications

In this paper, bamboo-like, O-doped carbon tubes with hierarchical pore structure have been fabricated by the direct pyrolysis of dual cross-linked polydivinylbenzene (PDVB) tubes. The bamboo-like, cross-linked PDVB tubes are firstly synthesized by cationic polymerization of divinylbenzene in cyclohexane using BF₃/Et₂O complex as the initiator. After a secondary cross-linking being imposed by Friedel–Crafts reaction in CCl₄ using anhydrous AlCl₃ as the catalyst, the obtained dual cross-linked, carboxylic acid functionalized PDVB tubes are directly subjected to pyrolysis, yielding bamboo-like, O-doped porous carbons. The resultant O-doped porous carbon tubes (BCTF-900, pyrolyzed at 900 °C) exhibit a trimodal pore structure (micro-, meso-, and macropores) with a relatively high specific surface area of 595 m² g⁻¹ and a low total pore volume of 0.37 cm³ g⁻¹. Such bamboo-like carbon tubes display good volumetric capacitive performance (254 F cm⁻³ at 0.5 A g⁻¹), moderate volumetric energy density (12.9 Wh L⁻¹ at 428 W L⁻¹), and excellent cycling stability (the capacitance retention has remained at 96.9% after 10000 cycles at 2 A g⁻¹). Due to their unique bamboo-like architecture and trimodal pore structure, the PDVB-derived carbon tubes should have widely application prospect.