From adsorption of rare earth elements on TiO2 nanotubes to preconcentration column application

Abstract

Selective adsorption of La, Ce, Y and Nd rare earth elements (REEs) from aqueous solution was performed using TiO2 nanotubes. Kinetic study reveals that REEs adsorption on TiO2 nanotubes is highly enhanced at pH 5 (acetate buffer). The experimental parameters keys such as pH, eluent concentration and flow rate are investigated. The desorption of REEs prior to ICP analysis is also studied. From thermodynamic study, the adsorption heats, are REEs atomic radius dependent, which opens a new route for the selective separation. An engineered packed column with TiO2 nanotubes was used under continuous flow for the REEs extraction. Our method yields excellent recovery (> 98%) of REEs, and the column can be regenerated up to 20 cycles.