High-temperature preparation and electrochemical properties of TiO2 anatase phase-mounted carbon aerogels

Abstract

TiO2 anatase phase-mounted carbon aerogels (CAs) were synthesized via the sol–gel polymerization of a mixture of resorcinol, formaldehyde, and tetrabutyl orthotitanate, followed by gelation, supercritical drying, and carbonization in N2 atmosphere. Ethanol was selected as the solvent in the sol–gel polymerization process. The morphology and microstructural characteristics of the TiO2-mounted carbon aerogel sample were obtained using thermogravimetry, transmission electron microscopy, scanning electron microscopy, N2 adsorption–desorption, and X-ray diffraction methods. The total pore volume and average pore sizes increased with TiO2 addition. Titania phase in anatase form was found to be more homogeneously distributed in the CAs at 900 °C. The anatase–rutile transformation did not take place at carbonization temperatures from 500 to 1100 °C and cyclic voltammetry measurements showed that the TiO2-mounted CAs exhibit good reversibility and high specific capacity as electrode materials, and the anatase in the carbon structure were not involved in the redox reactions. Electrochemical impedance spectroscopy demonstrated that the CA electrode behaves as an excellent capacitor with low resistance.