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

Abstract

A novel hybrid nanocomposite has been successfully fabricated for persulfate (S 2 O 8 2− ) detection. It can be easily prepared by grafting silicomolybdate (SiMO) and poly(3,4-ethylenedioxythiophene) (PEDOT) on multi-walled carbon nanotubes (MWCNT) to form the SiMO-PEDOT/MWCNT hybrid composite. The SiMO-PEDOT film formation is initiated through the electropolymerization of EDOT monomers. The 10 monomers are firstly electropolymerized to form the positive PEDOT and then the positive polymers are attractive to the negative SiMO, resulting in the electrocodeposition on electrode surface. It shows three significant redox couples and the redox peak currents can be enhanced by using a MWCNT-modified electrode. Morphological features were studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The electrode shows good activity towards S 2 O 8 2− reduction with low overpotential 15 (E pc = 0 V). Amperometric response provides linear range of 1-3333 μM with sensitivity of 2928.9 μA mM -1 cm -2 , detection limit of 1×10 -6 M (S/N = 3), and response time of 2.3 s. The SiMO-PEDOT/MWCNT electrode can effectively analyse S 2 O 8 2− due to its low overpotential, high sensitivity, good stability, fast response, and low cost.

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

“…7 There are several reports that provide the sensitivity and limit of the detection (LOD) of a few developed peroxodisulfate sensors which have been presented in Table 1 in the original papers. 80,81,101 Some groups claim that their developed electrosensors for the detection of S 2 O 8 2− anions offer higher sensitivity as well as lower LOD values with a wider linear range for the calibration curve of the concentrations of S 2 O 8 2− anions. However, most of them utilized Pb or organic dyes (Prussian blue, 88 natural red, 102 poly brilliant cresyl blue, 101 naphtol green, 97 celestine blue 81 ) in which case they are not eco-friendly.…”

“…80,81,101 Some groups claim that their developed electrosensors for the detection of S 2 O 8 2− anions offer higher sensitivity as well as lower LOD values with a wider linear range for the calibration curve of the concentrations of S 2 O 8 2− anions. However, most of them utilized Pb or organic dyes (Prussian blue, 88 natural red, 102 poly brilliant cresyl blue, 101 naphtol green, 97 celestine blue 81 ) in which case they are not eco-friendly. When utilizing immobilized organic dyes, the detection of S 2 O 8 2− anions was achieved in the presence of mediators.…”

Carbon Nanotube-Conducting Polymer Composites as Electrode Material in Electroanalytical Applications

“…One of them is the electrochemical technique that is studied with the composite electrode prepared by the combination of electropolymerized silicomolybdate (SiMO) and PEDOT on MWCNT/GCE. The SiMO-PEDOT/MWCNT electrode can effectively analyze S 2 O 8 2− due to its low overpotential, high stability, fast response, low cost, and high sensitivity with a 10 −6 M detection limit [86]. Nitrite is a versatile chemical compound used in a wide range of applications from dye manufacture to food preservation.…”