Tungsten concentration influence on the structural, electronic, optical and photocatalytic properties of tungsten–silver codoped titanium dioxide

Abstract To activate the wide functionalities of TiO 2 in photoelectrochemical applications, tungsten–silver codoped TiO 2 with different tungsten doping concentrations were synthesized using hydrothermal method. The codoped TiO 2 displayed pure anatase phase with strong absorption in visible light region describing the possible modification in electronic band structure due to codoping. Transmission electron microscopy observation shows that nano-particles have spherical morphology with uniform particle size distribution. X-ray photoelectron spectroscopy (XPS) verified the existence of tungsten and silver in the TiO 2 network, responsible for tuning the absorption edge and improving the photoactivity. The photoactivity of synthesized nano-materials was tested by photodegradation of methylene blue under visible light irradiations. All the synthesized codoped samples exhibit enhanced photo-response compared to that of undoped TiO 2 . Among all the codoped samples, the one with tungsten doping concentration of 3.5 at% possesses the best photocatalytic activity attributed to the synergistic effect between the dopants and optimal doping concentration.