Facile preparation of electroactive amorphous α-ZrP/PANI hybrid film for potential-triggered adsorption of Pb2+ ions

An electroactive hybrid film composed of amorphous alpha-zirconium phosphate and polyaniline (alpha-ZrP/PANI) is controllably synthesized on carbon nanotubes (CNTs) modified Au electrodes in aqueous solution by cyclic voltammetry method. Electrochemical quartz crystal microbalance (EQCM), scanning electron microscopy (SEM) and X-ray power diffraction (XRD) analysis are applied for the evaluation of the synthesis process. It is found that the exfoliated amorphous alpha-ZrP nanosheets are well dispersed in PANI and the hydrolysis of alpha-ZrP is successfully suppressed by controlling the exfoliation temperature and adding appropriate supporting electrolyte. The insertion/release of heavy metals into/from the film is reversibly controlled by a potential-triggered mechanism. Herein, alpha-ZrP, a weak solid acid, can provide an acidic micro-environment for PANE to promote the electroactivity in neutral aqueous solutions. Especially, the hybrid film shows excellent potential-triggered adsorption of Pb2+ ion due to the selective complexation of Pb2+ ion With oxygen derived from P-O-H of alpha-ZrP. Also, it shows long-term cycle stability and rapid potential-responsive adsorption/desorption rate. This kind of novel hybrid film is expected to be a promising potential-triggered ESIX material for separation and recovery of heavy metal ions from wastewater. (C) 2015 Elsevier B.V. All rights reserved.