Electrocatalytic Oxidation of 4‐Aminophenol Molecules at the Surface of an FeS₂/Carbon Nanotube Modified Glassy Carbon Electrode in Aqueous Medium

Abstract

FeS2/carbon nanotube (CNT) nanocomposites were synthesized and immobilized on the surface of a glassy carbon electrode (GCE) in order to investigate the electrocatalytic conversion of 4‐aminophenol (4‐AP) into p‐quinone in an aqueous medium. The reformed electronic properties (in terms of lowering of band‐gap energy and charge‐transfer resistance), as well as improved surface area, result in an enhanced redox reaction of 4‐AP in the presence of FeS2‐CNT NCs compared to that with FeS2 alone. The 4‐AP molecules undergo coupled two‐proton and two‐electron transfer quasi‐reversible redox reactions with a symmetry factor of 0.55 and standard rate constant (k°) of 0.8 cm s−1. Here, quinone imine is generated as an intermediate which is later converted into quinone in an irreversible hydrolysis reaction. The best catalytic performance can be obtained at the pH value of 7.0.

Electrochemical Detection of 2‐Nitrophenol Using a Glassy Carbon Electrode Modified with BaO Nanorods

“…Therefore, it is observed that BaO NRs/GCE has higher ability to transfer the charges in an electrochemical oxidation/reduction reaction. The similar observation has been reported in the identical conditions elsewhere [52,53] …”

“…The similar observation has been reported in the identical conditions elsewhere. [52,53] Figure 4(a) is shown in below about the scan rate (SR) of BaO NRs/GCE in 0.1 mM Fe(CN) 6 3À /4À by using cyclic voltammetric approach in a phosphate buffer medium at pH 7.0. The oxidation and reduction peaks are found at + 0.38 V and + 0.12 V respectively in 0.1 mM Fe(CN) 6 3À /4À , which are linearly shifted in a range of SR (50.0~325.0 mV/s) (Figure 4a).…”

Assessment of Melamine in Different Water Samples with ZnO‐doped Co3O4Nanoparticles on a Glassy Carbon Electrode by Differential Pulse Voltammetry

“…It has the less charge‐transfer resistance ( R ct ) compared to the bare GCE. Therefore, it can be concluded that the ZnO‐doped Co 3 O 4 NPs modified GCE has more ability to transfer the charges during electrochemical oxidation/reduction reaction as reported elsewhere [43,44] …”

Enzymeless Electrocatalytic Detection of Uric Acid Using Polydopamine/Polypyrrole Copolymeric film

“…We expect faster electron mobility on the PDA/PPY modified GCE, if the synthesis of PDA/PPY was successful. In EIS, the diameter of the semicircle denotes the charge‐transfer resistance (R ct ) at the surface of the electrode . As presented in Fig 4(a), the bare GCE displayed an increased R ct diameter compared to the PDA/PPY modified GCE in a solution containing 0.1 M PBS and 0.5 mM UA.…”