Kinetic study of Cu(II) adsorption on nanosized BaTiO3 and SrTiO3 photocatalysts

In this study, nanoparticles with perovskite structure (nano-SrTiO3 and nano-BaTiO3) were synthesized via a co-precipitation method, and their photocatalytic and adsorption characteristics were investigated. Both of them exhibited some photocatalytic activity and possessed a high adsorption capacity for copper ions. Further, the pseudo-first-order model was found to be more suitable to fit the experimental data. Moreover, it suggested that the Langmuir model was more adequate in simulating the adsorption isotherm. The maximum adsorption capacity was 370.4 mg/g and 200.0 mg/g for nano-SrTiO3 and nano-BaTiO3, respectively. The negative apparent free energy confirmed that the Cu2+ adsorption onto the nano-photocatalysts was a spontaneous process. The underlying mechanism of adsorption of Cu(II) onto nano-perovskites could be due to the ion exchange and surface complexation. From the results. SrTiO3 and BaTiO3 nanoparticles may be an effective material for Cu2+ removal and, together with its photocatalytic activity, may be suitable for environmental remediation applications. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.