RESUMO
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. METHOD: 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. CONCLUSION: 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.
