NANOSTRUCTURED TiO2 SENSITIZED WITH PORPHYRINS FOR SOLAR WATER-SPLITTING

Nanostructured TiO2 sensitized with porphyrins for Solar water-splitting.The production of hydrogen from water using solar light is very promising for generations of an ecologically pure carrier contributing to a clean, sustainable and renewable energy system. The selection of specific photocatalyst material for hydrogen production in photoelectrochemical cells (PECs) is based on some important characteristics of semiconductor, such as photo-corrosion and chemical corrosion stability, photocatalytic potential, high sensitivity for UV-visible light. In the present paper, different nanocrystalline TiO2 photoanodes have been prepared via wet-chemical techniques followed by annealing treatment and sensitized with porphyrins and supramolecular complexes of porphyrins. The so obtained photocatalysts were characterized with UV-VIS absorption spectroscopy and spectrofluorimetry. The purpose of these experiments is to show if the prepared materials possess the necessary photocatalytic characteristics and if they can be used with success in H2 production from water decomposition in PECs

Luminescence study of some yttrium tantalate-based phosphors

WOS: 000289599600042Yttrium tantalate (YTaO4), yttrium niobium-tantalate (YTaNbO4), yttrium niobate (YNbO4), europium and terbium activated yttrium tantalate (YTaO4:Eu, YTaO4:Tb) and europium activated yttrium niobate (YNbO4:Eu) phosphors were prepared by solid-state reaction, from a homogeneous mixture consisting of Y2O3, Eu2O3, Tb4O7, Ta2O5, Nb2O5 and Na2SO4 as flux. Photoluminescence (PL), thermally stimulated luminescence (TSL), X-ray diffraction (XRD) and scanning electron microscopy (SEM) of yttrium tantalate based phosphors are reported. In the present study TSL characteristics of these phosphors were first investigated and reported after exposure to beta, UV (311 nm) and X-ray radiations. (C) 2011 Elsevier B.V. All rights reserved