Enhanced Electrocatalytic Behaviour of Poy(aniline-co-2-hydroxyaniline) Coated Electrodes for Hydrogen Peroxide Electrooxidation

Abstract

Polymer-coated electrodes are widely used for the detection and oxidation of hydrogen peroxide (H 2 O 2 ). Conducting polyaniline (PANI), poly (2-hydroxyanilne) (PHA), and their copolymer poly(aniline-co-2-hydroxyaniline) (PACHA) were electrochemically synthesized on a gold substrate for H 2 O 2 detection and analysis. Cyclic voltammetry (CV), square wave voltammetry (SWV), and differential pulse voltammetry (DPV) techniques were used for electroanalysis. Both PACHA and PANI greatly reduced the gold overpotential for H 2 O 2 oxidation with enhanced current densities. The PACHA-and PANI-coated electrodes showed oxidative peaks at 0.30 and 0.50 V, respectively, in the presence of 1.4 × 10 −6 M H 2 O 2 , while PHA-coated electrodes exhibited no response. The fabricated electrodes displayed a linear response towards H 2 O 2 in range of 2 × 10 −7 to 1.4 × 10 −6 M, with very low detection limits (LODs) of 1 × 10 −7 M (for PACHA) and 1.15 × 10 −7 M (for PANI) evaluated from CV data. In case of SWV and DPV, the LODs were found to be 1.78 × 10 −7 M (for PACHA) and 1 × 10 −7 M (for PANI), respectively. The materials exhibit high sensitivity of 650 A/Mcm 2 and show good stability. The PACHA-coated electrode shows better capacitance (1.84 × 10 −3 F) than PHA-(2.52 × 10 −4 F) and PANI-coated (1.17 × 10 −3 F) electrodes.

Cephradine-Capped Gold Nanoparticle Modified Glassy Carbon Electrode for Trace Level Sensing of Triphenyltin Hydroxide

“…Other reports regarding the sensitive detection of other analytes through CV have been presented elsewhere. [34][35][36] Effect of electrolyte.-Three electrolytes, acetate buffer, phosphate buffer and Britton Robinson buffer (BRB) were tested for selecting electrolyte with the best choice in order to get best shaped voltammogram with highest peak current for determination of TPTH. According to Fig.…”

Cyclic Voltammetry, Kinetics, Thermodynamic and Molecular Docking Parameters for the Interaction of Nickel Chloride with Diphenylthiocarbazone

“…The electrochemical behavior reduction or and oxidation [29,30] of NiCl2 was studied at different temperatures (293.15, 303.15, and 313.15K) in the presence of potassium ferrioxalate as mediators in 0.1 M citric acid since normally nickel ions gave no waves in acidic media. This method is simple to discuss the electrochemical behavior of Ni(II) ions.…”

Performance Improvement of Gold Electrode towards Methanol Electrooxidation in Akaline Medium: Enhanced Current Density Achieved with Poly(aniline-co-2-hydroxyaniline) Coating at Low Overpotential

“…When studying electrooxidation of methanol in basic media, it is assumed that hydroxyl ions, methanol, and gold are the responsible species for the oxidation process. During the methanol oxidation reaction in basic media, hydroxyl ions produce abundantly, which are strongly adsorbed by the gold electrode surface by producing numerous gold oxide ions, which then make way for methanol oxidation [36]. It is also observed that there is continuous peak shift towards negative potential with the increase in methanol concentration, which means that oxidation of methanol on PACHA coated gold electrodes is a diffusion controlled phenomenon [26,58] or may also be due to oxide layer formation [36].…”

“…During the methanol oxidation reaction in basic media, hydroxyl ions produce abundantly, which are strongly adsorbed by the gold electrode surface by producing numerous gold oxide ions, which then make way for methanol oxidation [36]. It is also observed that there is continuous peak shift towards negative potential with the increase in methanol concentration, which means that oxidation of methanol on PACHA coated gold electrodes is a diffusion controlled phenomenon [26,58] or may also be due to oxide layer formation [36]. Elsewhere electrooxidation of 1 M methanol in 0.5 M NaOH was reported around −0.1-0.2 V on pladium-polyaniline coated gold electrodes [52].…”

“…Because of these advantages it was applied in the fields of sensors [29,35] and Zn-rechargeable batteries [28]. PACHA coated gold sheet electrode was recently reported for electrooxidation of ascorbic acid in citrate [36]. To the best of our knowledge, this fascinating derivative of polyaniline has not been tested in the electrooxidation of methanol in either acidic or basic media.…”