Effects of O2 and H2O2 on TiO2 photocatalytic efficiency quantified by formaldehyde formation from tris(hydroxymethyl)aminomethane
2013 (English)In: Journal of AOTS. Advanced Oxidation Technologies, ISSN 1203-8407, Vol. 16, no 1, 16-22 p.Article in journal (Refereed) Published
The impact of O2 and H2O2 on the efficiency of TiO2 photocatalysis has been studied in this work. Tris(hydroxymethyl)aminomethane (Tris) was used to probe the efficiency. Upon hydrogen abstraction by e.g. hydroxyl radicals from Tris, formaldehyde is formed. This product was detected and quantified using a modified version of the Hantzsch method. A significant increase in the formaldehyde production rate was observed upon addition of O2 or H2O2. It was also found that O2 and H2O2 are equally effective in scavenging the photo-excited electron, which is probably a result of their similar adsorption properties. A strong concentration dependence, independent of O2 or H2O2 content, was found at low Tris concentrations (<100 mM). Adsorption studies of H2O 2 onto the TiO2 surface were performed in order to explore the rate controlling reactions. The results show that H2O 2, having a stronger adsorption affinity than Tris towards the photocatalytic surface, govern the kinetics, but only until a monolayer is built up.
Place, publisher, year, edition, pages
2013. Vol. 16, no 1, 16-22 p.
Binary Metal-Oxides, Titanium-Dioxide, Heterogeneous Photocatalysis, Hydrogen-Peroxide, Solid-Solutions, Degradation, Suspensions, Adsorption, Kinetics, Surface
IdentifiersURN: urn:nbn:se:kth:diva-117784ISI: 000314536000002ScopusID: 2-s2.0-84872537118OAI: oai:DiVA.org:kth-117784DiVA: diva2:603069
QC 201302052013-02-052013-02-052013-11-21Bibliographically approved