Polystyrene (PS) honeycomb patterned porous films filled with titanium dioxide (TiO2) nanoparticles were prepared by a modified breath figure method. The honeycomb patterned porous films filled with TiO2 nanoparticles were obtained by pouring titanium butoxide over partially dried PS solution during the fabrication of the PS films under humid conditions. TiO2 nanoparticles were obtained by the hydrolysis of titanium butoxide in the condensed micro water droplets at the PS solution/air interface. Morphology, elemental mapping, X-ray diffraction (XRD), X-ray photoelectron spectroscopy, and UV-Visible analysis support the formation of TiO2 nanoparticles in the honeycomb patterned pores. XRD studies showed that the formed TiO2 nanoparticles are anatase. Photo-activity of the incorporated TiO2 nanoparticles was examined by the change of the water contact angle of the films before and after UV irradiation. Water contact angles was decreased by UV irradiation, implying the transformation of the surface from hydrophobic to hydrophilic due to the photo-induced wettability by TiO2. (C) 2017 Elsevier Ltd. All rights reserved.