Determination of peroxodisulfate ion using composite film containing naphthol green B and multi-walled carbon nanotubes

Abstract

An electrochemically active composite film which contains multi-walled carbon nanotubes (MWCNTs) incorporated with naphthol green B (NGB) was synthesized on glassy carbon, gold and indium tin oxide electrodes by potentiodynamic method. The presence of MWCNTs in the composite (MWCNTs-NGB) film modified electrodes mediates redox reaction of Fe III/II present in NGB, whereas no redox reaction of NGB occurred at the bare electrode. The electrochemical impedance spectroscopy studies revealed that NGB and MWCNTs present in MWCNTs-NGB composite film enhances electron shuttling between the reactant and electrode surface. The surface morphology of the MWCNTs and MWCNTs-NGB were studied using atomic force microscopy, which revealed that NGB incorporated and covered the MWCNTs on the modified electrode. The MWCNTs-NGB composite film exhibits promising enhanced electrocatalysis towards S 2 O 8 2À . The response of S 2 O 8 2À at MWCNTs and MWCNTs-NGB composite films was measured using both cyclic voltammetry and i-t curve techniques. The linear concentration range of S 2 O 8 2À determination at MWCNTs-NGB composite film was from 15.9 mM to 7.1 mM. The sensitivity of MWCNTs-NGB composite film towards S 2 O 8 2À was À301.9 mA mM À1 cm À2 , and the limit of detection was 6.9 mM. These above values are better than the values obtained at MWCNTs film.

Review—Electroreduction of Peroxodisulfate: A Review of a Complicated Reaction

“…4 Other techniques are spectrophotometry, titration, and ion chromatography. 7,97 However, these methods do not provide information on the exact quantity of peroxodisulfate anions in a solution. In addition, there are several drawbacks for these methods as sample pre-treatments are needed, the procedures are time-consuming, and skilled workers are required, particularly for the ion chromatography technique.…”

A highly sensitive persulfate sensor based on a hybrid nanocomposite with silicomolybdate doping poly(3,4-ethylenedioxythiophene) on multi-walled carbon nanotubes

“…. 42 Good electrocatalytic activities of CNTs are expected so that CNTs hybrid composites with organic or inorganic compounds are worthy to study in the electrochemical sensors.…”

“…40,41 Multi-walled carbon nanotubes (MWCNT) incorporated with naphthol green B was used to determine S 2 O 8 2− . 42 Good electrocatalytic activities of CNTs are expected so 10 that CNTs hybrid composites with organic or inorganic compounds are worthy to study in the electrochemical sensors.…”

Spectrophotometric determination of peroxymonosulfate anions via oxidative decolorization of dyes induced by cobalt

“…To the best of our knowledge, there have been a number of available methods to determine the PMS concentration in aqueous solution, and these methods may include chromatography, 12 chemiluminescence, 13,14 iodometric, 15 spectrophotometric, 16 and lm methods. 17 The chromatography method was rst proposed by Zhang and co-workers 12 who reported the characteristic peak of PMS at 260 nm by high performance liquid chromatography. For the liquid chromatography method, it is a common practice to use a Varian Polaris 3C-18A column and a mixture of methanol and phosphoric acid buffer as the separation column and mobile phase, respectively.…”