Titanate nanofibers sensitized with nanocrystalline Bi2S3 as new electrocatalytic materials for ascorbic acid sensor applications

Here is described a new method for titanate nanofibers (TNF) modification with nanocrystalline semiconducting bismuth sulphide (Bi2S3) nanoparticles in order to obtain new materials with innovative electrocatalytic properties. The TNF surface modification was achieved by in situ nucleation and growth of nanocrystalline metal sulphide particles through a single-source approach. Using bismuth diethyl-dithiocarbamate complex as the metal chalcogenide precursor, nanocrystalline of Bi2S3 particles were obtained over the TNF surface. The prepared materials were characterized and the results evidence that a thin layer of crystalline Bi2S3 nanosheets is covering the TNF' entire surface. After immobilization on a glassy carbon electrode, the nanocomposite structured surface was electrochemically characterized. The ability of the modified electrodes for sensor applications was tested towards the electrocatalysis for the ascorbic acid oxidation reaction. The results obtained indicate that these are very interesting materials to be used for sensing at pH 7, displaying a vitamin C linear response in the 1-10 mM concentration range.