Effect of humidity treatment on the structure and photocatalytic properties of titania mesoporous powder

In the work presented here, mesoporous titania (MT) powders is synthesized by sol–gel method using amphiphilic triblock copolymer as a template at two different levels of relative humidity (RH); 20 and 80%. Various techniques such as small angle X-ray diffraction (SAXRD), wide angle X-ray diffraction (XRD), UV–visible spectroscopy, high resolution transmission electron microscopy (HRTEM), Fourier transformed infra red (FTIR) spectroscopy and N 2 -adsorption/desorption analysis were utilized to study the prepared samples. Further, the photocatalytic activities of the prepared samples were evaluated from the photo-degradation analysis of methylene blue (MB). For the sample treated with 80%RH the formation of an ordered mesoporous structure with a high specific surface area (172 m 2 g −1 ), mesoporosity (48%) and enhanced photocatalytic activity were obtained compared to those of the sample subjected to 20%RH. The observed increased MB degradation for the latter is mainly attributed to the formation of higher specific surface area and mesoporosity. The availability of highly ordered open pore channels could provide increased contacts between reactants in the solution and the active sites on the surfaces of MT particles.