title: Raman and electrochemical impedance studies of sol-gel titanium oxide and single walled carbon nanotubes composite films.
abstract: Titanium oxide grown by a sol-gel route on single-walled carbon nanotubes was studied by Raman and Electrochemical Impedance techniques and compared with mixtures obtained by mechanical grinding. In spite of the superior dispersion of single-walled carbon nanotubes bundles in sol-gel composites, the lost of the small-diameter carbon nanotubes in the oxidizing sol-gel bath was inferred from their Raman spectra and the lower capacitive current of the voltammograms in 0.1 M H2SO4. We proposed proton electrosorption as the main charge storage mechanism for sol-gel composites, favoured by the hydroxylation and n-type conductivity of the oxide, while electrodes based on mixtures were dominated by double-layer charging, developing some pseudocapacitance with potential cycling due to the reversible oxidation of carbon nanotubes. Comparsion with TiO2/Carbon Blacks composites shows the effective role of single-walled carbon nanotubes as templates to control the mesoporous nature of sol-gel composite electrodes.
authors: Centro de Investigación en Energía-UNAM, Apartado Postal 34, Temixco 62580, MOR, México.
authors: M E
authors: ME
authors: Rincón
authors: M E
authors: ME
authors: Trujillo-Camacho
authors: M
authors: M
authors: Miranda-Hernández
authors: A K
authors: AK
authors: Cuentas-Gallegos
authors: G
authors: G
authors: Orozco
mesh_terms: D017097:Electric Impedance; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D005782:Gels; D008422:Materials Testing; D053768:Metal Nanoparticles; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D044367:Phase Transition; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014025:Titanium / Q000737:chemistry*
chemical_list: D005782:Gels; D037742:Nanotubes, Carbon; D010087:Oxides; C009495:titanium dioxide; D014025:Titanium