Effect of aggregation of methylene blue dye on TiO2 surface in self-cleaning studies

The present paper shows that the aggregation behavior of methylene blue in the monomer, dimer or aggregated forms is responsible for the inconsistency in the photocatalytic performance studies in various photocatalysts materials. The aggregation behavior of MB and its influence on photocatalytic degradation of the dye during photocatalytic performance study has been characterized by UV–visible absorption spectroscopy. The results indicate that the photocatalytic degradation of dyes depends not only on the intrinsic parameters of photocatalysts but also on the aggregation behavior of the pollutant on the catalyst surface.