One-step hydrothermal preparation of TiO2/WO3 nanocomposite films on anodized stainless steel for photocatalytic degradation of organic pollutants

• Published in: Thin solid films 2013-12, Vol.548, p.299-305
• Main Authors: Zhan, W.T., Ni, H.W., Chen, R.S., Wang, Z.Y., Li, Y.W, Li, J.H.
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts: preparations and properties; Chemistry; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; General and physical chemistry; General, apparatus; Materials science; Nanocomposite film; Nanopore arrays; Nanoscale materials and structures: fabrication and characterization; Other topics in nanoscale materials and structures; Photocatalytic activity; Physics; Stainless steel; Structure and morphology; thickness; Surface physical chemistry; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Thin film structure and morphology; Titanium oxide; Tungsten oxide
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.09.010

TiO2/WO3 nanocomposite film was deposited on anodized stainless steel by one step hydrothermal reaction. Polished stainless steel foil was anodized to form nanopore arrays on the surface that is favorable for the immobilization of photocatalyst. The TiO2/WO3 nanocomposite film prepared in 0.01mol/L (NH4)2TiF6 and 0.0066mol/L Na2WO4 solution at 120°C for 3h exhibits the maximum photocatalytic activity, which is five times higher than that of pure TiO2 film and eight times higher than that of pure WO3 film. As compared with the pure TiO2 film, the main absorption edge of the WO3/TiO2 nanocomposite film shifts toward visible region and the absorption intensity is obviously improved. The nanocomposite film has a preferable crystallinity of anatase TiO2 and the monoclinic WO3, as revealed by X-ray diffraction and X-ray photoelectron spectroscopy. Scanning electron microscopy images show that the nanocomposite film is homogenous in size distribution and uniform in morphology. The high resolution transmission electron microscopy images further demonstrate the formation of mixed crystal between WO3 and TiO2 nanoparticles. The excellent photocatalytic activity of the nanocomposite film should be attributed to the formation of heterojunction between TiO2 and WO3 nanoparticles that can facilitate the separation of photo-generated electron–hole pairs. •TiO2/WO3 nanocomposite film on anodized stainless steel by hydrothermal deposition•The anodized stainless steel offered a favorable substrate to immobilize the photocatalyst.•The photocatalytic activity of TiO2/WO3 film is significantly higher than that of TiO2 film.•The heterojunction between TiO2 and WO3 leads to excellent photocatalytic activity.