There is an increasing need for simple and reliable procedure for characterization of photocatalytic activities of developed materials. The aim of work was to develop a method for the determination of quantum yields of supported photocatalysts by employing an aqueous solution of a coumarin. Coumarin is oxidized in the presence of irradiated TiO2 to 7-hydroxycoumarin, which could be fluorimetrically detected at low concentrations. Additionally, also a newly defined parameter, so called mass efficiency, was introduced as an advantageous way of defining the photocatalytic activities.
COBISS.SI-ID: 1064187
The disappearance of thiacloprid was studied applying various photochemical AOPs and different TiO2 photocatalysts. Higher surface area resulted in a more pronounced synergic effect but an increasing amount of TiO2 did not influence the degree of the synergy. This supports the theory that the synergy is a consequence of adsorption of ozone on the TiO2 surface. No synergy was observed in photocatalytic degradation of thiacloprid in the presence of dissolved iron(III) species. This goes against the literature for different other organic compounds.
COBISS.SI-ID: 1422587
A new method for determination of self-cleaning activity of photocatalytic surfaces is proposed. It is based on the deposition of a transparent solid layer comprising terephthalic acid over the photocatalytic surface. After irradiation, among the other degradation products also a hydroxyterephthalic acid was formed, which is a fluorescent molecule and it was detected by HPLC-FLD or spectrofluorimeter. The novel method is accurate, highly sensitive and reproducible, therefore it represents a promising option to be considered in standardization efforts in the field of photocatalysis.
COBISS.SI-ID: 1230331