Solar-light induced photodegradation of organic pollutants over CdS-pillared zirconium-titanium phosphate (ZTP)

Abstract

With an attempt to extend the light absorption towards visible range and inhibit the rapid recombination of excited electrons and holes during photoreaction, a new type of photocatalysts, cadmium sulfide pillared zirconium-titanium phosphate (CdS-ZTP) powders were synthesised by two step sulfurisation route. The photocatalysts were characterised by SAXS. N(2) adsorption-desorption, DRUV-vis, PL, SEM/EDX, XPS, TPD and photocurrent measurements. The samples exhibited a unique property of optical absorption in UV and visible region with a wave length, lambda <= 450 nm followed by a clear long tail up to 700 nm. CdS pillaring has increased the photocatalytic efficiency of ZTP by three folds by increasing surface area, visible light sensitivity and decreasing band gap energy to 2.81 eV. The pillared materials showed excellent activity towards degradation of organic pollutants under solar light illumination. Amongst all the photocatalysts, 15CdS-ZTP showed the best photoactivity in the range of 70-94% and 64% towards the degradation of textile dyes and phenol, respectively in 180 min. (C) 2011 Elsevier B.V. All rights reserved.