Bandgap Modulation of TiO2 and its Effect on the Activity in Photocatalytic Oxidation of 2-isopropyl-6-methyl-4-pyrimidinol

Abstract

Nano-size TiO 2 particles were obtained using various mesoporous materials and the particle sizes were determined by the pore sizes of mesoporous materials. The bandgap increments due to quantum size effect were observed in both anatase TiO 2 and rutile TiO 2 . The bandgap increment in anatase TiO 2 did not affect the efficiency of photocatalytic oxidation of 2-isopropyl-6-methyl-4-pyrimidinol. However, the bandgap increment in rutile TiO 2 enhanced the photocatalytic activity by virtue of the increase in redox potential of TiO 2 .

Properties of Electrospun TiO2Nanofibers

“…Besides the bandgap, the grain size will affect the area's surface; for a constant volume, the bigger the particle is, the less its surface area will be [19]. For anatase phase, the TiO 2 photovoltaic efficiency is improved with the decrease of the grain size; this is due to the increase in the photons absorption and improved interfacial characteristics [20].…”

Purification of Toxic Compounds in Water and Treatment of Polymeric Materials

“…The bandgap increment in rutile TiO 2 enhances the photocatalytic oxidation rate of IMP by virtue of the increase in redox potential of TiO 2 . However, the bandgap increment in anatase TiO 2 does not affect the efficiency of IMP photocatalytic oxidation (Lee et al 2005).…”

“…Major studies focused on the degradation mechanism of DNA bases (uracil, thymine, and cytosine) and the effect of coexistent ions on the activity of the photocatalyst (Dhananjeyan et al 1996(Dhananjeyan et al , 1997(Dhananjeyan et al , 2000aHorikoshi et al 1999;Jaussaud et al 2000;Horikoshi and Hidaka 2001;Calza et al 2004). Several reports dealt with the photocatalytic degradation of pyrimidine derivative pesticides such as diazinon and 2-isopropyl-6-methyl-4-pyrimidinol (IMP) (Kouloumbos et al 2003;Lee et al 2003Lee et al , 2005Oh et al 2006Oh et al , 2007. These studies are reviewed in this chapter.…”

Photoreaction of Au/TiO2 for hydrogen production from renewables: a review on the synergistic effect between anatase and rutile phases of TiO2

“…Anatase can therefore only be excited by UV light whilst rutile has a photo-response to UV light, as well as extending slightly into the visible light region [36]. It is generally accepted that the CB of anatase lies higher than that of rutile [37]; however there is still some debate about the relative positions between the anatase and rutile CBs [38], as well as the exact CB potentials for both of these TiO 2 polymorphs [39][40][41]. Furthermore anatase has an indirect BG whilst rutile has a direct BG, which may affect electron-hole recombination rates.…”