화학공학소재연구정보센터
Chemical Engineering Journal, Vol.229, 66-71, 2013
Self-rotating photocatalytic system for aqueous Cr(VI) reduction on TiO2 nanotube/Ti mesh substrate
In this study, a self-rotating photocatalytic system is applied to reduce toxic Cr(VI) to non-toxic Cr(III) in aqueous solution under UV irradiation. To overcome the limitation of powdery photocatalysis, a novel approach towards a photocatalytic system for aqueous Cr(VI) reduction including self-rotating TiO2 nanotubes on a Ti substrate (mesh type) was established. For the preparation of TiO2 nanotubes on the Ti substrate, Ti mesh (10 cm x 10 cm) was anodized at 50 V to 25 degrees C for 25 min with mixed electrolytes (NH4F-H2O-C2H6O2), and then annealed at 450 degrees C for 2 h in ambient oxygen at a flow rate of 400 mL min(-1). The fabricated TiO2 nanotube arrays were uniformly grown on Ti mesh and surface characterizations was performed through the measurements of SEM, XRD, and zeta potential. The HRT (Hydraulic retention time) and rotating speeds were significantly affected by inlet flowrate in this reactor being decreased and increased, respectively, with increasing inlet flowrate. Hence, the efficiency of photocatalytic Cr(VI) reduction was observed to be highest up to 95% at the 90 rpm. In addition, the rate of Cr(VI) reduction was increased by increasing the number of TiO2/Ti meshes. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.