Non-toxic poly(vinyl alcohol)/clay composites as electrode material for detection of 4-chlorophenol and 4-nitrophenol

Development of new electrode materials is necessary for the fabrication of sensors with low detection limits, high sensitivity and broad concentration range. Beside analytical parameters, the ability to replace rare and expensive metals, without additional pollution, is also expected from new materials. Materials based on non-toxic raw materials are presented in this paper. Clay-polymer nanocomposites consisting of Wyoming clay rich in montmorillonite and different loadings of poly(vinyl alcohol) (PVA) (10 wt% and 20 wt%, i.e. PVA10-W and PVA20-W samples) were synthesized. The intercalation of PVA into montmorillonite was confirmed by elemental, XRD and SEM analysis. The electrochemical behavior of synthesized electrode materials was tested using the electrochemical impedance spectroscopy and cyclic voltammetry. It was found that PVA/montmorillonite ratio influenced the performance of the composite-modified electrode. The detection of 4-chlorophenol and 4-nitrophenol on the investigated electrodes was tested using the square wave voltammetry. The analytical application of the electrodes was evaluated on a river water sample