Aggregate formation of eosin-Y adsorbed on nanocrystalline TiO2 films

► Adsorption isotherm of eosin-Y dye from solution onto nanocrystalline TiO2 films was obtained. ► A Langmuir-type adsorption isotherm was observed for eosin-Y dye adsorbed from acetonitrile solutions. ► A Freundlich-type adsorption isotherm was observed for eosin-Y dye adsorbed from ethanol solutions. ► From the analysis of the absorption spectra, structure of aggregates can be discussed.