Chromium has been commonly applied as an acceptor-type dopant for TiO2. Its ionic radius (0.052 nm) is smaller than that of the host Ti4+ ion (0.068 nm). The incorporation of trivalent ions, such as Cr, into the Ti sites of the TiO2 lattice leads to the formation of acceptors. These result in reducing the concentration […]

The increasingly apparent effects of global warming and resulting climate changes are forcing us to increase the use of renewable energy, such as solar energy. The global efforts in this directions aim to develop new energy conversion systems. The TiO2-based semiconductors are the promising candidates for the development of solar energy conversion systems with versatile […]

The photocatalytic effects of TiO2 have resulted in a wide range of its environmen­tally friendly applications (alternative to photocatalytic water purification and the generation of solar hydrogen fuel), including [1,126]: • • Antiseptic Coatings for Sanitary Areas. The antiseptic properties of TiO2 coatings are related to the light-induced bactericidal effect. The antiseptic coating can be […]

The change of the population of microorganisms in water depends on a number of factors, including: • Temperature • Intensity and energy of light • Composition of the aqueous environment • Alkalinity/acidity • Concentration of oxygen and oxidants • Exchange of mass (turbulence) The reproducibility of data requires that all the factors influencing the photocata­lytic […]

While the search for a high-performance photocatalyst intensifies, the technology at this stage is still remote from the commercial requirements. The major hurdles include: FIGURE 8.35 Kinetics of E. coli bacteria disinfection for undoped and N-doped TiO2, according to Liu et al. [10]. (Reproduced with permission from Y Liu, J Li, X Giu, C Burda, […]

Doping of TiO2 with aliovalent ions is the current major research strategy in the development of high-performance photocatalysts. The aim is to increase absorption of sunlight by reduction of the band gap through the incorporation of aliovalent ions [8,9-11, 71,97]. A range of anions (nitrogen, fluorine, carbon) and cations has been applied for doping [98,99]. […]

8.5.3.1 Deposition of Noble Metals A substantial number of reports have been accumulated on the effect of noble metals, such as Pt, on the photocatalytic performance of TiO2 [81-92]. This data indicates that the photocatalytic activity depends on surface dispersion of Pt, forming small islets, and the related ratio of the Pt/TiO2 areas. Sakthvitel et […]

The primary photo-induced reaction at the cathodic site is the reduction of molecular oxy­gen (Figures 8.30 and 8.32) [83, 95-97]. The progress of the cathodic reaction depends on the supply of oxygen to cathodic sites. The concentration of electrons in n-type semi­conductors is relatively high. Consequently, the supply of oxygen to the cathodic site is […]