Synthesis and characterization of Y3+-doped TiO2 nanocomposites for photocatalytic applications.

The TiO(2).[Y(2)O(3)](x) (x = 0.1-0.4) nanocomposites (NCs) with an average particle size of 74 nm were prepared by the method of chemical co-precipitation followed by hydrolysis (CPH). Their visible light photocatalytic activity was investigated for the degradation of congo red (CR) dye. All NCs showed improved degradation as compared to the polycrystalline samples of similar compositions prepared by the solid-state reaction (SSR) route (average particle size of a few micrometers), as well as to the pure TiO(2). The better photocatalytic activity of the NCs was attributed to their smaller particle size. Another comparison of the results with those obtained with Zn(2+)/Fe(3+) ions co-doped TiO(2) NCs, under similar experimental conditions, revealed that in the Y(3+)-doped NCs, particle size might not be the only factor responsible for the improved photocatalytic properties. It was concluded that the Y(3+) ion-mediated suppression of the unwanted e(-)/h(+) recombination could be the possible factor leading to additional enhancement.

Formation of TiO2 nanorings due to rapid thermal annealing of swift heavy ion irradiated films.

Amorphous thin films of TiO2 deposited by Pulsed Laser Deposition (PLD) method are irradiated by Swift Heavy Ion (SHI) beam. The irradiated films are subsequently annealed by Rapid Thermal Annealing (RTA) method. Atomic Force Microscopy (AFM) study reveals formation of nano-rings on the surface after RTA processing. Phase change is identified by Glancing Angle X-ray Diffraction (GAXRD) and Raman spectroscopy. Optical characterisation is carried out by UV-VIS absorption spectroscopy. Though no shift of absorption edge is observed after irradiation, RTA processing does show redshift.

Synthesis of nanodimensional TiO2 thin films.

Nanodimensional TiO2 has wide application in the field of photocatalysis, photovoltaic and photochromic devices. In present investigation TiO2 thin films deposited by pulsed laser deposition method are irradiated by 100 MeV Ag ion beam to achieve growth of nanophases. The nanostructure evolution is characterized by atomic force microscopy (AFM). The phases of TiO2 formed after irradiation are identified by glancing angle X-ray diffraction and Raman spectroscopy. The particle radius estimated by AFM varies from 10-13 nm. Anatase phase of TiO2 is formed after irradiation. The blue shift observed in UV-VIS absorption spectra indicates the nanostructure formation. The shape and size of nanoparticles formed due to high electronic excitation depend upon thickness of the film.