Smectite-chitosan-based electrodes in electrochemical detection of phenol and its derivatives

In this paper smectite-chitosan bionanocomposite (SМ-C) based on smectite (SM) from Crni Timok (Black Timok) basin, Serbia, was synthesized and characterized using chemical analysis, XRD and FTIR. The SM-C obtained was used for the modification of a glassy carbon electrode (GCE). The modified electrode (GCE/SM-C) was tested in the electrooxidation of phenol and different nitrophenols in acidic and alkaline solutions. Cyclic voltammograms (CV) obtained for GCE/SM-C, contrary to that obtained for the bare glassy carbon electrode, exhibited multiple oxidative peaks. The cathodic limit set to allow encompassing of nitro group reduction increased sensitivity for 4-nitrophenol detection. It also led to the appearance of additional peaks of 2-nitrophenol and decrease of the electrode passivation rate. The first-order derivative linear sweep voltammetry improved the sensitivity of the detection of different phenolic compounds from their mixed solution. The application of GCE/SM-C in alkaline environment led to increased current response while lowering the passivation rate. The quantitative determination of phenol and nitrophenols in a mixture, based on electrooxidation, had some disadvantages in both acidic and alkaline solution. Nevertheless, the concept of electrooxidation as a method for the detection and distinction of phenol and its nitro derivatives from water solution was proven. Bionanocomposites based on smectite and chitosan used as electrode material Simultaneous detection of phenol and nitrophenols [Display omitted] •Smectite-chitosan bionanocomposite applied as electrode material.•Simultaneous detection of phenol and nitrophenols.•The effects of recording parameters on cyclovoltammograms of nitrophenols.•The influence of acidic and alkaline media on detection was investigated.