Modification of TiO₂ nanotubes by WO₃ species for improving their photocatalytic activity

Highlights: • WO₃/titania nanotubes are synthesized at low temperature (383 K) by a novel approach. • WO₃/titania nanotubes present enhanced photocatalytic activity. • The substitution of Ti⁴⁺ by W⁶⁺ does not occur in nanocomposites at 383 K. • Diffuse reflectance spectra of WO₃/TNTs exhibit a red shift due to WO₃ connection. • The optimal degradation rate of MO could reach 95% within 2 h irradiation. - Abstract: WO₃/TiO₂ nanotubular composite was synthesized at low temperature (383 K) by a novel approach. WO₃ nanoparticles were loaded on anatase TiO₂ nanotubes through the reaction between (NH₄)₆W₇O₂₄·6H₂O and aqueous solution of HCl. The obtained products were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV–vis diffuse reflectance spectroscopy (UV-DRS). Degradation of methyl orange was employed to investigate the photocatalytic activity of the products. Results show that, among the samples with different concentrations of WO₃, W₁₀T with the atomic ratio W/Ti of 10% presents optimal degradation rate. This degradation rate is about 95% within 2 h under UV light irradiation, which is much higher than that of pure TiO₂ nanotubes