Rapid carbon activation via microwave irradiation of nongraphitic carbon doped with metallic potassium and tetrahydrofuran (THF) Sang-Eun Chun a , J.F. Whitacre a, b, * a Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA b Department of Engineering and Public Policy, Carnegie Mellon University, Pittsburgh, PA 15213, USA highlights graphical abstract  We demonstrate a rapid process to synthesize microporous carbon from nongraphitic carbon source through microwave-assisted exfoliation.  While avoiding restrictive processing conditions of current chemical acti- vation, microporous structure carbon can be efficiently synthesized.  The specific areal capacitance reveals as high as 16.5 mF cm 2 in 1 M NaNO 3 aqueous solution.  The electrochemical properties of the microwave-activated carbon show significant promise for use in super- capacitor electrode. K-THF-nongraphitic carbon microwave (2 mins) article info Article history: Received 4 December 2012 Received in revised form 4 April 2013 Accepted 4 April 2013 Available online 11 April 2013 Keywords: Microwave activation Rapid activation process Nongraphitic carbon precursor Electrochemical capacitor Microporous carbon Pore shape abstract We report here a rapid process to synthesize microporous carbon from nongraphitic carbon source through microwave-assisted exfoliation in a non-inert environment. A ternary compound of potassium- nongraphitic carbon-tetrahydrofuran (THF) was prepared and then heating by microwave irradiation for 2 min widens the interstices between adjacent graphene layers in ternary compound, inducing micro- porous texture with a large amount of ultramicropores. Exploiting microwave heating allows for efficient and rapid synthesis of activated carbon compared with commonly used chemical activation process. After microwave irradiation on nongraphitic carbon, the constituent stacked graphene layers were broken and the specific surface area of 563 m 2 g 1 was developed. The feasibility of an electrode material for supercapacitor was estimated by cyclic voltammetry and galvanostatic charge/discharge cycling. The specific areal capacitance reveals as high as 16.4 mF cm 2 in 1 M NaNO 3 aqueous solution, which is significantly larger than values found in traditional activated carbons made for use in electrochemical double layer capacitors. Without restrictive processing conditions of chemical activation, microporous structure carbon can be efficiently and rapidly synthesized via microwave irradiation for possible elec- trochemical capacitor electrode. Ó 2013 Elsevier B.V. All rights reserved. 1. Introduction Good materials for electrochemical capacitor electrodes should have good electrical conductivity, be electrochemically stable, and have a high density of electrochemically active surface area that can interact with dissolved electrolyte species [1e3]. A variety of * Corresponding author. Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA. Fax: þ1 412 268 7596. E-mail address: whitacre@andrew.cmu.edu (J.F. Whitacre). Contents lists available at SciVerse ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour 0378-7753/$ e see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jpowsour.2013.04.012 Journal of Power Sources 240 (2013) 306e313