Facile synthesis, structural, optical and photocatalytic properties of mesoporous Ag2O/TiO2 nanoheterojunctions

We have successfully synthesized ball-like mesoporous Ag2O/TiO2 nanohybrids with extremely high surface area (similar to 2779 m(2)/g) and excellent photodegradation activity by a facile wet chemical method. The synthesis involves CTAB-assisted self-assembly of TiO2 nanocrystals and Ag nanoparticles into ball-like mesoporous Ag2O/TiO2 hybrid nanostructures. Raman spectroscopy, transmission electron microscopy, BET surface area analysis and X-ray diffraction were employed to determine the structural characteristics of the synthesized Ag2O/TiO2 nanohybrids, while the optical behaviour was explored by optical absorption spectroscopy and photoluminescence spectroscopy. A growth mechanism underlying the formation of ball-like mesoporous Ag2O/TiO2 nanohybrids is tentatively proposed. The photodegradation activity of mesoporous Ag2O/TiO2 nanohybrids was studied by evaluating sunlight induced photodegradation of RhB and MB dyes and 4-nitrophenol. Mesoporous Ag2O/TiO2 nanohybrids exhibited excellent photodegradation activity for the decomposition of RhB, MB and 4-nitrophenol. The observed excellent photodegradation activity of mesoporous Ag2O/TiO2 nanohybrids is ascribed to the combined effects of their large surface area leading to efficient adsorption of pollutants, improved solar light harvesting and efficient separation of photoinduced electron-hole pairs due to formation of Ag2O/TiO2 nanoheterojunctions.