A film of niobium oxide was immobilized on a SiO2/C carbon-ceramic matrix (specific surface area 270 m2 g-1) and characterized by N2 adsorption-desorption isotherms, scanning electron microscopy, X-ray photoelectron spectroscopy and atomic force microscopy. This new carbon-ceramic material, SiO2/C/Nb 2O5, was used for construction of electrodes, and it shows ability to improve the electron-transfer between the electrode surface and ascorbic acid. The electrocatalytic oxidation of ascorbic acid was made by differential pulse and cyclic voltammetry techniques, making it potentially useful for developing a new ascorbic acid sensor. © 2010 Elsevier B.V.