Photoelectrochemical and photocatalytic activity of TiO2-WO3 heterostructures boosted by mutual interaction

Abstract The TiO2-WO3 heterostructures with superior interfacial interactions were synthesized by simple solvothermal method followed by calcination. The electrical property of the heterostructures was tuned by varying the amount of TiO2 and WO3 to achieve higher photoelectrochemical activity. The prepared samples were characterized by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning transmission electron microscopy and UV–vis diffuse reflectance spectroscopy. The strong interaction in the interface of TiO2-WO3 heterostructures and the solar spectral response of TiO2 and WO3 reduce the electron-hole pair recombination rate and enhance the photoelectrochemical activity. The TiO2-WO3 heterostructures show 17 times higher photon-to-hydrogen conversion efficiency than pure TiO2 and WO3 under solar light and almost complete removal of organic pollutant in 60 min under visible light. The TiO2-WO3 heterostructures also show good adsorption capacity for organic pollutants. The present study demonstrates that the prepared TiO2-WO3 heterostructures are promising materials for efficient water splitting as well as adsorption and photocatalytic removal of organic pollutants.