A novel approach for synthesis of visible-light-active nano-crystalline TiO2 photocatalyst

Silver doped tio2 nanoparticles were prepared by combination of sol-gel and arc discharge methods in liquid. the ag/tio2 nanoparticles were characterized by x-ray diffraction (xrd), transmission electron microscopy (tem) and ultra violet-visible absorption spectroscopy (uv-vis). the visible light photocatalytic activities were successfully demonstrated for the degradation of rhodamine b (rh. b) as a standard organic compound under the irradiation of 90 w halogen light for 2 h. the results revealed that the ag/tio2 nanoparticles extended the light absorption spectrum toward the visible region and significantly enhanced the rh. b photodegradation under visible light irradiation. 0.05 gr ag/tio2 nanoparticles exhibited highest photocatalytic efficiency. it has been confirmed that the ag/tio2 nanoparticles could be excited by visible light (e<3.2 ev). the significant enhancement in the ag/tio2 nanoparticles photocatalytic activity under visible light irradiation can be ascribed to the effect of doped noble metal ag by acting as electron traps in tio2 band gap.