Escherichia coli inactivation by N, S co-doped commercial TiO2 powders under UV and visible light

Sulphur, nitrogen-doped TiO2/graphene oxide composites as a high performance photocatalyst

“…The higher surface area of the samples may be attributed to the large areas of GO and TiO 2 nanoparticles, and the embedding of the dopants in the TiO 2 network also results in larger pore volume, pore size and surface area. Such architecture plays an important role in catalyst design for its ability to improve the molecular transport of reactants and products [33,38,39]. Adsorption on the catalyst surface area facilitates the aggregation of the reactant molecules for the photoreactions.…”

“…The oxygen vacancy and Ti 3þ species act as a hole trap. While the electrons and holes were generated in the initial stage of visible light illumination, the defects on the titania surface or in the bulk could suppress the recombination of electron-hole pairs and hence extend their lifetime [37][38][39]. For a better understanding of charge recombination behavior in the as-prepared samples, we investigated the electron transport in sample films via to transient current.…”

Solar photocatalysis for water disinfection: materials and reactor design

“…6 By contrast, Cu and N-doped photocatalyst-coated bottles appeared to demonstrate improved bacterial photoinactivation relative to 30 undoped titania, and these effects appeared to persist in the absence of UV wavelengths. 6 There are a number of recent reports present in the literature on the visible light inactivation of bacteria [22][23][24][25][26]68 , but the effective and consistent use of these materials for long term solar disinfection is yet to be developed. …”

“…In some cases, the formation of singlet oxygen, a less oxidative, reactive oxygen species was reported to be responsible for the 40 bacterial inactivation. [20][21][22] The hole, produced by the visible light irradiation, in the mid-gap or isolated energy levels (as a result of doping) would not have the adequate redox potential to oxidise organic molecules of the pollutant. Therefore the methylene blue degradation is not always a good reaction system to determine the 45 photocatalytic properties of solar or visible light activated materials.…”

“…TiO 2 photocatalysis, therefore, has real potential for disinfection of resistant microorganisms. 7,[22][23][24][25][26] In addition to the hydroxyl radicals, other 15 oxidative species such as superoxide anions and singlet oxygen can also be created ( Figure 2). The first report of TiO 2 photocatalytic inactivation of bacteria was in 1985 by Matsunaga et al 27 , and since then a large number of microorganisms have been reported to be photocatalytically 20 inactivated.…”