Titanium dioxide nanoparticles have been obtained by sol-gel process. Titanium isopropoxide was hydrolized in acidic medium at pH values between 0.5 and 1. The hydrolysis was catalyzed with HCl, HNO3 or HClO4, and studied their influence in the formation of titanium dioxide crystalline phases, i.e. rutile, anatase and brokite phases. The peptization process was studied with Visible and Fourier Transform Infrared (FTIR) spectroscopic techniques. Hydrothermal treatment at 220 °C for 12 hours permits the fabrication of well defined nanoparticles as it was observed by Transmission Electron Microscopy (TEM). The crystal structure was obtained by X-ray diffraction (XRD). Only the anatase phase was obtained using HClO4, however using HCl and HNO3 the anatase/rutile ratio is related to the pH of the initial acidic solution and the amount of anatase phase has increased when the pH of this soluti...

This work was supported by the Peruvian-Argentinean 321-2009-CONCYTEC OAJ Project and MINCYT-CONCYTEC PE/09/01 and PE/11/02

ZnO nanorods (ZnO NRs) were grown on ZnO seeded polyethylene tert-phtalate(PET) substrates obtained from recycled soda bottles at low temperatures (90°C) from Zn2+precursors in alkaline aqueous solution. The ZnO seeds were deposited on the PET substrates by spray gel (SG) or dip coating (DC) from a ZnO methanol sol. In the case of SG, the PET substrate was heated at 90 °Cduring the spray process. By the other hand the ZnO seed layers obtained by dip coating were heated at 90°C or 130°C for 10 minutes among coatings. Before seeding two procedures were made on PET surface forimproving seed adhesion: 1) PET surface was mechanically roughened with sand paper 1200. 2) PET surface was chemically treated with a solution of NaOH in ethanol. The relationship between the microstructure of the ZnO NRs films as function of the PET surface treatment and the photocatalytic antibacterial activity f...

ZnO nanorods (ZnO NRs) were grown on ZnO seeded polyethylene tert-phtalate (PET) substrates obtained from recycled soda bottles at low temperatures (90 °C) from Zn2+ precursors in alkaline aqueous solution. The ZnO seeds were deposited on the PET substrates by spray gel (SG) or dip coating (DC) from a ZnO methanol sol. In the case of SG, the PET substrate was heated at 90 °C during the spray process. By the other hand the ZnO seed layers obtained by dip coating were heated at 90 °C or 130 °C for 10 minutes among coatings. Before seeding two procedures were made on PET surface for improving seed adhesion: 1) PET surface was mechanically roughened with sand paper 1200. 2) PET surface was chemically treated with a solution of NaOH in ethanol. The relationship between the microstructure of the ZnO NRs films as function of the PET surface treatment and the photocatalytic antibacterial act...

ZnO nanorods (NRs) films, nitrogen-doped (ZnO:N), and ZnO doped with nitrogen and decorated with silver nanostructures (ZnO:N-Ag) NRs films were vertically supported on undoped and N doped ZnO seed layers by a wet chemical method. The obtained films were characterized structurally by X-ray diffraction. Morphological and elemental analysis was performed by scanning electron microscopy, including an energy dispersive X-ray spectroscopy facility and their optical properties by Ultraviolet-Visible Spectroscopy. Analysis performed in the NRs films showed that the nitrogen content in the seed layer strongly affected their structure and morphology. The mean diameter of ZnO NRs ranged from 70 to 190 nm. As the nitrogen content in the seed layer increased, the mean diameter of ZnO:N NRs increased from 132 to 250 nm and the diameter dispersion decreased. This diameter increase occurs simultaneousl...