Photocatalytic activity of predominantly rutile mixed phase Ag/TiV oxide nanoparticles under visible light irradiation

Nanoscale synthesis of silver sensitized titanium vanadium mixed-metal (Ag/TiV) oxides was done employing sol–gel technique. The physico–chemical properties of the material were examined using XRD (X-ray diffraction), SEM (Scanning Electron Microscopy), EDAX (Energy Dispersive X-ray Spectroscopy), HR-TEM (High Resolution Transmission Electron Microscopy), XPS (X-ray Photoelectron Spectroscopy), UV-DRS and Photoluminescence analysis (PL). The results indicated the presence of predominantly rutile mixed phase particles of 20–30 nm grain size. Identically prepared TiV as well as Ag/TiV oxide catalyst showed enhanced and extended visible light absorption with an absorption upper limit, λ ≥ 550 nm. The visible light photocatalytic activity of Ag/TiV oxide showed an increase of about three and seven times compared to TiV oxide and Degussa P25 respectively, in the rate of degradation of phenol. The reason for the enhanced visible light activity of Ag/TiV oxide may be ascribed to elevated and extended absorption due to combined effect of dopant induced band gap reduction and visible light induced surface plasmon resonance of the Ag nanoparticles. The photocatalytic activity is complemented by localized charge traps and Ag assisted charge separation in the system as well.