Characterization of Li-doped WO3 nanowires and their enhanced electrocatalytic oxidation of ascorbic acid

Li-doped WO3 nanowires have been hydrothermally prepared and characterized mainly via spectroscopic methods. Both the hexagonal structure distortion and morphology evolution induced by Li doping reveal a lattice expansion of about 0.07 A. Also, the residence of oxygen vacancy and the enlargement of external surface areas positively correlate with the narrowing of energy band. Subsequently, the electrocatalytic oxidation of ascorbic acid using a Li-doped WO3 film-coated electrode performs a 13% and 21% negative shift of the oxidation overpotential compared with a WO3 film-coated electrode and a bare glassy carbon electrode, respectively. A preliminary mechanism has been proposed on the basis of relevant model analyses.