Enhanced photocatalytic and disinfection activities of silver loaded ordered mesoporous titanium dioxide for water treatment

Abstract

In the present paper ordered mesoporous titanium dioxide (TiO₂) has been synthesized by using the nanocasting method with SBA-15 as a hard template and titanium alkoxide as the precursor. The silver has been loaded onto the obtained ordered mesoporous TiO₂ using photoreduction method. The physicochemical properties of as-prepared and calcined silver loaded mesoporous titanium dioxide (SMTO) have been characterized by various techniques. The XRD pattern confirms the existence of tetragonal anatase-rutile mixed phases of TiO₂ with a crystallite size of the range of 12-15 nm. SEM and TEM images show that the aggregation of nanocrystalline phase results in the formation of nanometer sized mesoporous TiO₂ with a well-defined spherical morphology and retained ordered structure. The as-obtained samples exhibit good photocatalytic degradation of rhodamine B, Congo red and methyl orange dyes as model water contaminant at room temperature with UV light irradiation. The samples under study also show substantial disinfection properties against E. coli & S. aureus used as a model strain. The significant enhancement of the photocatalytic and disinfection activities of the SMTO materials is mainly attributed to their absorbed more photons and reduced electron-hole pair recombination due to synergic effect of porosity of the ordered structure and Ag-impregnated nanoparticles, respectively.