Synthesis and photocatalytic activity of Ti[1 − x]V x O[2 − y]C y whiskers in hydroquinone oxidation in aqueous solutions

Abstract

Ti1−x V x O2−y C y (0 ≤ x ≤ 0.10 and x = 0.50) whiskers having the anatase structure were synthesized via thermolysis of vanadium-doped titanium glycolate of composition Ti1−x V x (OCH2CH2O)2 (0 ≤ x ≤ 0.10 and x = 0.50). The starting reagents used to prepare Ti1−x V x (OCH2CH2O)2 were mixtures of coprecipitated titanium and vanadyl hydroxides, which were heated in ethylene glycol at T ≤ 200°C: (1 − x)TiO(OH)2 + xVO(OH)2 + 2HOCH2CH2OH = Ti1−x V x (OCH2CH2O)2 + 3H2O↑. Thermolysis of vanadium-doped titanium glycolate in various gas media over a wide range of temperatures is useful to prepare titania samples doped with both vanadium and carbon to form a phase of the general composition Ti1 − x V x O2 − y C y whiskers prepared by thermolyzing Ti1 − x V x (OCH2CH2O)2 in air at 450°C were found to have a high photocatalytic activity in hydroquinone oxidation in aqueous solutions irradiated in the UV spectral range; the photocatalyst’s activity increases with increasing vanadium concentration. When hydroquinone was irradiated in the blue, the maximal catalytic activity was discovered in a sample of composition Ti0.50V0.50O2−y C y . Quantum-chemical calculations support experimental data that the double doping of titania (Ti1−x V x O2−y C y ) enhances its photocatalytic activity compared to undoped anatase or anatase doped in one sublattice: Ti1−x V x O2 and TiO2−y C y .