The design, fabrication, and photocatalytic utility of nanostructured semiconductors: focus on TiO2-based nanostructures

TLDR: Applications and future directions of nanostructured TiO2 are considered in the context of various photoinduced phenomena such as hydrogen production, electricity generation via dye-sensitized solar cells, photokilling and self-cleaning effect, photo-oxidation of organic pollutant, wastewater management, and organic synthesis.

Abstract: Recent advances in basic fabrication techniques of TiO 2 -based nanomaterials such as nanoparticles, nanowires, nanoplatelets, and both physical- and solution-based techniques have been adopted by various research groups around the world. Our research focus has been mainly on various deposition parameters used for fabricating nanostructured materials, including TiO 2 -organic/inorganic nanocomposite materials. Technically, TiO 2 shows relatively high reactivity under ultraviolet light, the energy of which exceeds the band gap of TiO 2 . The development of photocatalysts exhibiting high reactivity under visible light allows the main part of the solar spectrum to be used. Visible light-activated TiO 2 could be prepared by doping or sensitizing. As far as doping of TiO 2 is concerned, in obtaining tailored material with improved properties, metal and nonmetal doping has been performed in the context of improved photoactivity. Nonmetal doping seems to be more promising than metal doping. TiO 2 represents an effective photocatalyst for water and air purification and for self-cleaning surfaces. Additionally, it can be used as an antibacterial agent because of its strong oxidation activity and superhydrophilicity. Therefore, applications of TiO 2 in terms of photocatalytic activities are discussed here. The basic mechanisms of the photoactivities of TiO 2 and nanostructures are considered alongside band structure engineering and surface modification in nanostructured TiO 2 in the context of doping. The article reviews the basic structural, optical, and electrical properties of TiO 2 , followed by detailed fabrication techniques of 0-, 1-, and quasi-2-dimensional TiO 2 nanomaterials. Applications and future directions of nanostructured TiO 2 are considered in the context of various photoinduced phenomena such as hydrogen production, electricity generation via dye-sensitized solar cells, photokilling and self-cleaning effect, photo-oxidation of organic pollutant, wastewater management, and organic synthesis.