Powder semiconductor photocatalysis in aqueous solution: An overview of kinetics-based reaction mechanisms

Probing the activities of UV and visible-light absorbing photocatalyst powders using a resazurin-based photocatalyst activity indicator ink (Rz Paii )

“…TiO2, CdS, WO3 and C3N4, when used as a dispersion in deaerated, aqueous solution, appear able to mediate the UV (365 nm) photocatalysed reduction of Rz to Rf by glycerol, i.e. reaction (3). Under the same conditions, but using visible (455 nm) light, the same reaction is promoted by the visible-light absorbing semiconductors, CdS, WO3 and C3N4.…”

“…In almost all such commercial products the active ingredient is a semiconductor, SC, where SC = TiO2, which absorbs ambient light (UV light if TiO2 is used), from a solar or artificial light source, to produce electron-hole pairs, which can recombine, in the bulk or at the surface of the semiconductor or, most importantly for semiconductor photocatalysis, react with surface-adsorbed species [3]. Most commercial photocatalytic commercial materials use the SC, usually TiO2, to mediate the photo-oxidation of adsorbed organic species, either dissolved in solution, or in the form of volatile organic carbons, to their mineral form, with the concomitant reduction of adsorbed O2 to water, i.e.…”

Kinetics of reduction of a resazurin-based photocatalytic activity ink

“…In order to try to established the true nature of the initial kinetics of reaction (2) It is generally accepted that most examples of semiconductor photocatalysis fit a Langmuir-Hinshelwood type kinetics expression [23], i.e.…”

Photocatalytic Behavior of Water-Based Styrene-Acrylic Coatings Containing TiO2 Sensitized with Metal-Phthalocyanine Tetracarboxylic Acids

“…Many efforts have been made in order to find new types of photocatalytic materials, which are able to promote generation of species that react with different types of organic compounds and to efficiently remove pollutants from aqueous media or from solid surfaces [1][2][3]. Besides classical semiconducting oxides, namely TiO 2 and ZnO, only CeO 2 has proved a convenient behavior for this type of applications, despite the rapid recombination of photo-generated electrons and holes.…”