Environmental remediation of Cr(VI) solutions by photocatalytic reduction using Ag-Er(OH)3 nanocomposite

A hydrothermal method was use to prepare Er(OH)(3) nanoparticles, and a photoassisted deposition method was used to deposit silver onto the surface of those nanoparticles. Er(OH)(3) and Ag/Er(OH)(3) nanocomposites were characterized by BET, XRD, XPS, PL, UV-Vis and TEM measurements. The photocatalytic performance of the nanoparticles with respect to the photocatalytic reduction of chromium(VI) under UV light irradiation was determined. The results reveal that the silver particles were well dispersed onto the surface of the Er(OH)(3) nanoparticles. Additionally, the surface area of the Ag/Er(OH)(3) nanocomposites was observed to be smaller than that of the Er(OH)(3) nanoparticles due to the blocking of some pores of the Er(OH)(3) nanoparticles by the deposition of silver particles. The Ag/Er(OH)(3) nanocomposites (0.15 wt%) exhibit the lowest band gap and highest photocatalytic activity for the reduction of Cr(VI). The photocatalytic performance of the 0.15 wt% Ag/Er(OH)(3) nanocomposites was stable after the reuse of the nanoparticles for the reduction of Cr(VI) after five uses. (C) 2015 Elsevier B.V. All rights reserved.