Title: Tuning the porous texture of carbon materials derived from chlorination of Ti(C5H5)2Cl2 for potential electrochemical capacitors
Authors: D.J. Araujo-Pérez; P. González-García; M. Poisot; L. García-González
Addresses: Centro de Investigación en Micro y Nanotecnología, Universidad Veracruzana, 94294, Boca del Río, Veracruz, México ' CONACYT–CIDESI, Centro Nacional de Tecnologías Aeronáuticas (CENTA), Carretera Estatal 200 Querétaro-Tequisquiapan km 23 No. 22547, 76270, Colón, Querétaro, México ' Instituto de Química Aplicada, Universidad del Papaloapan, 68301, San Juan Bautista Tuxtepec, Oaxaca, México ' Centro de Investigación en Micro y Nanotecnología, Universidad Veracruzana. 94294, Boca del Río, Veracruz, México
Abstract: Variation of the reaction time at 30, 60, 90 and 120 min, respectively, on the chlorination of Ti(C5H5)Cl2, at 900°C, has delivered carbon materials with a tuneable mixture of mesopores and micropores, surface areas as high as 855 m2g-1 and pore volume of 0.56 cm3g-1. The cyclic voltammetry measurements yielded capacitances as high as 198 Fg-1 at scan rate of 5 mVs-1 in 6M-KOH as an electrolyte. Electrochemical impedance spectroscopy (EIS) analyses showed that the shape of the Nyquist plots, of the fabricated carbon electrodes, showed an almost purely diffusive process at low reaction times and a mixture of kinetic and diffusive processes for the materials chlorinated at longer times; additionally, the capacitance values, calculated by electrochemical impedance, varied from 139 F/g to 22 F/g, corroborated the behaviour observed by cyclic voltammetry. The effective dielectric permittivity calculations showed values ranging from 11 to 18, being the K+ ions more accessible than the OH−.
Keywords: carbon materials; surface features; cyclic voltammetry; capacitances; electrochemical impedance.
DOI: 10.1504/IJMMP.2018.097782
International Journal of Microstructure and Materials Properties, 2018 Vol.13 No.6, pp.419 - 438
Received: 25 Oct 2017
Accepted: 27 Jul 2018
Published online: 09 Feb 2019 *