Electrospun polyacrylonitrile/cyclodextrin-derived hierarchical porous carbon nanofiber/MnO2 composites for supercapacitor applications

The aim of this study is to develop the templateless fabrication of hierarchical porous carbon nanofiber (CNF)/MnO2 composites (PMnCD) derived from polyacrylonitrile (PAN)/cyclodextrin (CD) and investigate their morphological and electrochemical properties to determine the different capabilities of inclusion complexes (ICs) formed by alpha-CD, beta-CD and gamma-CD. Among the three CD phases, the PMnCD(beta) composite using beta-CD exhibits a hierarchical porous structure with large specific surface area of 499 m(2) g(-1), and total pore volume of 0.32 cm(3) g(-1), which helps with adsorption efficiency and accumulation of hydrated molecules for double-layer formation. In addition, the numerous mesopores and nitrogen functionalities of the PMnCD(beta) composite provide fast diffusion channels for electrolyte ions and higher attractive interactions with electrolyte ions through the pseudocapacitive character. As a result, the PMnCD(beta) electrode has a high specific capacitance of 228 Fg(-1 )at 1 mAcm(-2), maximum energy density of 25.3-16.0 Whkg(-1) in the power density range of 400-10,000 Wkg(-1), and excellent cycling stability of more than 94% after 10000 cycles in aqueous solution, thereby offering potential applications for supercapacitors. (C) 2020 Elsevier Ltd. All rights reserved.