Liquid phase deposition of tungsten doped TiO2 films for visible light photoelectrocatalytic degradation of dodecyl-benzenesulfonate

The technique of liquid phase deposition (LPD) was developed for the preparation of tungsten doped TiO2 (W-TiO2) films in this study. The doped films were characterized with scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The UV–vis spectra showed that the films extended the absorption wavelength into visible light range after being doped with 1–7% (at.%) content of W. Under the illumination of visible light, the W-TiO2 film showed a sensitive photocurrent response. Accordingly, the visible light photocatalytic degradation of dodecyl-benzenesulfonate (DBS) was tested and 5% W-TiO2 film showed the highest degradation efficiency up to 84.8% after 4-h treatment. When +1.0 V anodic bias potential and visible light were simultaneously applied, the degradation efficiency of DBS over the 5% W-TiO2 film was significantly improved to 92% after 90 min. The effects of anodic bias potential, initial pH value, and initial concentration of DBS on the PEC degradation of DBS were investigated.