WO<sub>3</sub>-TiO<sub>2</sub> Nanocomposite and its Applications: A Review

Design and development of nanostructure of titanium dioxide (TiO 2 ) assemblies has gained significant scientific interest and become the most studied material as it exhibits promising functional properties. Nevertheless, formation of TiO 2 nanocomposite thin film, especially WO 3 -loaded TiO 2 nanotubes without bundling is essential for high efficiency in many potential applications, including photocatalytic oxidation related applications, solar cell related applications, electrochromic devices and sensing related applications. Thus, this chapter aims to summarize on the development of an efficient WO 3 -loaded TiO 2 nanotubes catalyst for the improving the performance for charge carriers transportation and extended the spectral response of TiO 2 to visible spectrum. In fact, coupling TiO 2 with W 6+ species will lead to an additional electronic state in the band-gap of nanocomposite thin film, which in turn affect a change in the electronic and functionality of TiO 2 itself. As a result, band gap narrowing effects could expand the range of excitation light to the visible region and provide sites that slow down the recombination of charge carriers. To bring more TiO 2 related applications to the point of commercial readiness and viability in terms of performance and cost, substantial research on the development of high efficient nanocomposite thin film (WO 3 -TiO 2 ) is necessary. In this chapter, different synthesis strategies and research findings for WO 3 -TiO 2 nanocomposite thin film as well as its prospects in potential applications will be reviewed in detail.