from first principles PP-I-1

PP-V-9Electrocatalytic Detection of Arsenic at Silver-Doped Zeolite-CarbonNanostructured-Epoxy Composite ElectrodesManea F. 1 , Baciu A. 1 , Pop A. 1 , Remes A. 1 , Pode R. 1 , Schoonman J. 21 ”Politehnica” University of Timisoara, Timisoara, Romania2 Delft University of Technology, Delft, The Netherlandsflorica.manea@chim.upt.roA study of two substrates namely carbon nanotubes and carbon nanofibers for silver zeolitecarbonnanostructured-epoxy composite electrodes envisaging arsenic(III) electrodetection viaanodic stripping voltammetry/amperometry is reported. Morphological characterization ofboth composite electrodes was carried out by scanning electron microscopy, and a gooddispersion of both carbon filler and silver-doped zeolite within the epoxy matrix was revealed.Mechanistic aspects for arsenic deposition and stripping have been investigated on bothelectrodes using cyclic voltammetry technique. Both composite electrodes allowed to detectan arsenic signal using anodic stripping with a deposition potential of -0.4 V/SCE for120 seconds at the potential value of about +0.2 V/SCE. The results of arsenic detectionsensitivity using cyclic voltammetry in relation with the electrocatalytic activity of carbonnanotubes towards arsenic deposition and stripping led to the selection of silver zeolite-carbonnanotubes composite electrode for further detection studies. Differential-pulsed voltammetry,chronoamperometry and multiple-pulsed amperometry techniques were applied for arsenicdetection via anodic stripping. In comparison with other results reported [1, 2], betterelectroanalytical performance in relation with the sensitivity and the lowest limit of detectionfor arsenic detection were achieved in this study. Also, a recovery degree of 98% was foundfor arsenic electrodetection using differential-pulsed voltammetry for spiked water samples.References:[1] A.O.Simm, C.E.Banks, R.G.Compton, Electroanal. 17 (2005) 1727.[2] G,Cepria, N.Alexa, E.Cordos, J.R.Castillo, Talanta 66 (2006) 875.318