Effect of Au content on the enhanced photocatalytic efficiency of mesoporous Au/TiO2 nanocomposites in UV and sunlight

Detoxification of harmful dyes through nonconventional catalytic processes is getting thrust in light of environmental remediation. Current work reveals synthesis of gold-titania (Au/TiO2) mesoporous nanostructure and its enhanced photocatalytic performance for degradation of alizarin dye. Optically, Au/TiO2 shows a characteristic surface plasmonic absorption band at 520 nm, whereas X-ray diffraction (XRD) pattern reveals the anatase phase of TiO2 with fcc unit cell structure and tetragonal geometry. X-ray photon spectroscopy depicts (Au 4f(7/2) at 84.0 and Au 4f(5/2) at 87.7 eV) the elemental state of gold (Au-0). Specific surface area was witnessed to decrease with increase of Au content (169, 141, 130, and 119 m(2)/g for 1, 2, 3, and 4 wt%, respectively). The mesoporous Au/TiO2 nanocomposite showed higher catalytic performance in comparison to commercial nano-TiO2 (P25), which is credited to better charge delocalization at metal semiconductor interface. The reusability studies of the photocatalyst exhibited more than 98% degradation of the dye even after 10 consecutive cycles.