Tris(hydroxymethyl)aminomethane as a probe in heterogeneous TiO 2 photocatalysis
2012 (English)In: Journal of AOTS. Advanced Oxidation Technologies, ISSN 1203-8407, Vol. 15, no 2, 392-398 p.Article in journal (Refereed) Published
In this work we present a new route to probe the efficiency of aqueous TiO 2 photocatalysis using Tris(hydroxymethyl)aminomethane (Tris). Hydrogen abstracting species such as hydroxyl radicals react with Tris through hydrogen abstraction, which leads to the formation of formaldehyde. Formaldehyde was subsequently detected and quantified spectrophotometrically at 368 nm using a modified version of the Hantzsch reaction. The effect of Tris concentration on the photocatalytic production of formaldehyde was studied in the range 0.1-500 mM Tris. A strong concentration dependence was observed below 100 mM, which indicates that not all photo-produced (hydroxyl) radicals are scavenged at Tris concentrations below 100 mM. Therefore, in order to assess the maximum efficiency of the photocatalytic system, Tris concentrations above 100 mM are required. To evaluate the effect of O 2 on the formaldehyde yield in the reaction between Tris and the hydroxyl radical, a gamma radiolysis study was performed where Tris solutions saturated with O 2 and N 2, respectively, were irradiated in parallel and the yield of formaldehyde was compared. These results showed that O2 does not influence the formaldehyde yield.
Place, publisher, year, edition, pages
2012. Vol. 15, no 2, 392-398 p.
Relative Photonic Efficiencies, Rutile Phase-Transition, Electron-Spin-Resonance, Titanium-Dioxide, Semiconductor Photocatalysis, Oxidative-Degradation, Aqueous Suspensions, Hydroxyl Radicals, Quantum Yields, Adsorption
IdentifiersURN: urn:nbn:se:kth:diva-101596ISI: 000306963800019ScopusID: 2-s2.0-84864538063OAI: oai:DiVA.org:kth-101596DiVA: diva2:548240
QC 201208302012-08-302012-08-302013-11-21Bibliographically approved