Comparison of methods for evaluation of activity of photocatalytic films.
OBJECTIVE
This work aims to investigate the correlation between the photocatalytic activity determined by methylene blue bleaching (DIN 52980), stearic acid degradation, and degradation of acetone in gas phase.


METHODS
The photocatalytic TiO(2) coatings included in this investigation ranged from thin commercially available coatings (Activ(TM) and BioClean(TM)) and ready to use suspensions (Nano-X PK1245) to lab-produced PVD and sol-gel coatings. XRD analysis of the photocatalytic coatings showed that all the coatings consisted of nanocrystalline anatase, although the thickness and porosity varied considerably.


RESULTS
The study showed that the reproducibility of the activity measurements was good. However, more importantly, the investigation showed that there is a good correlation between the activities determined by the different methods even though the characteristics of the photocatalytic coatings and the organic probe molecules varied considerably.


CONCLUSIONS
The overall findings of this work suggest that there is a good correlation between the investigated methods. These results are promising for the future work concerning standardization of methods for determination of the activity of photocatalytic films.
Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Niels Bohrs Vej 8, 6700, Esbjerg, Denmark. mes@bio.aau.dk
Morten E
ME
Simonsen
Martin B
MB
Sørensen
Erik G
EG
Søgaard
D000096:Acetone / Q000737:chemistry; D002384:Catalysis; D004785:Environmental Pollutants / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D008751:Methylene Blue / Q000737:chemistry; D055668:Photochemical Processes; D013229:Stearic Acids / Q000737:chemistry; D014025:Titanium / Q000737:chemistry
D004785:Environmental Pollutants; D013229:Stearic Acids; D000096:Acetone; C009495:titanium dioxide; C031183:stearic acid; D014025:Titanium; D008751:Methylene Blue