Heterogeneous photocatalytic Cr(VI) reduction with short and long nanotubular TiO 2 coatings prepared by anodic oxidation

TRAID, HERNÁN D.; LITTER, MARTA I.; HENRIKSON, EDGARD R.; VERA, MARÍA L.; ARES, ALICIA E.

MATERIALS RESEARCH BULLETIN

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2018 vol. 97 p. 150 - 157

0025-5408

AcceptedNanotubular TiO2 coatings prepared by anodic oxidation of titanium were evaluatedhe first time in the photocatalytic Cr(VI) reduction in the presence of EDTA. Smnanotubes (SN) were prepared by using aqueous hydrofluoric acid as electrolyte, aong nanotubes (LN) were made by using an ethylene glycol solution containammonium fluoride and water. The samples were characterized by scanning electmicroscopy, X-ray diffraction and UV-Vis diffuse reflectance spectroscopy. Tphotocatalytic reactions were performed using [Cr(VI)]0 = 0.8 mM, a EDTA/Cr(Vmolar ratio = 1.25 and pH 2. The photocatalytic activity increased with the applvoltage due to an increase of the average diameter, wall thickness and length. The mactive SN coating yielded 98% of Cr(VI) transformation after 300 min, while allsamples achieved a complete transformation in the same time or less. The photocatalyactivity was in almost cases higher than that of a P25 supported sample.