PROCEEDINGS OF THE SHEVCHENKO SCIENTIFIC SOCIETY

Chemical Sciences

Archive / Том LVI 2019

Yaroslav KOVALYSHYN1, Ivanna TERENYAK1, Mykhailo GONCHAR2, Oleksandr RESHETNYAK1, Ivan SALDAN1

1Ivan Franko National University of Lviv Kyryla and Mefodia Str. 6, 79005 Lviv, Ukraine
2Institute of Cell Biology NAS of Ukraine, Drahomanova Str., 14-16, 79005 Lviv, Ukraine

DOI: https://doi.org/10.37827/ntsh.chem.2019.56.112

ALDEHIDES OXIDATION ON PAN-CNT-ELECTRODE DECORATED WITH EXTRAFINE PLATINUM PARTICLES

The purpose of this work is to investigate the electrochemical process of oxidation of a number of aldehydes and formic acid on a working electrode coated with pAn-mCNT-Pt composite at various values of potentials. Initial CNT were modified by treatment with paranitrophenyldiazonium tetrafluoroborate in presence of a reducing agent and subsequent reduction of paranitrophenyl groups to paraaminophenyl groups. Polyaniline and modified BNT composite was synthesized by chemical method. Electrochemical deposition of extrafine platinum particles was carried out according to a two-electrode scheme on an electrode coated with a layer of pAn-mCNT. For chronoamperometric studies, a three-electrode scheme with a working graphite electrode coated with pAn-mCNT-Pt, an auxiliary platinum electrode and saturated chlorine silver as reference electrode was used. The studies were carried out in a 1/15 M aqueous dibasic sodium phosphate solution, which was added to phosphoric acid to reach pH = 3. Potentials of the working electrode were equal to +0.5 V; + 0.4 V; + 0.3 V; +0.2 V; +0.1 V; 0.0 V; -0.1 V. Comparison of sensitivities of aldehydes oxidation processes reveals that aldehydes are oxidized at comparable speeds in the potential region from -0,1 V to +0,3 V. At higher potentials the oxidation rate of acetaldehyde and propanal decreases sharply. This fact can be used for the separate detection of formaldehyde (FA) and acetaldehyde (AA) or formaldehyde (FA) and propanal (PA). For example, in the field of potentials lower than +0.3 V, a chemosensor, on the base of the synthesized composite, will give a total response on FA and AA, at potentials higher than + 0.3 V − only on FA. The sensitivity of the response to propanal is slightly lower than in the case of FA and AA. At potentials higher of +0.4 V, sensitivity of the sensor is significantly reduced, although no electrochemical processes that could interfere with aldehydes oxidation. It should be noted special nature of oxidation formic acid. At potentials higher than +0.1 V, sensitivity of the test electrode to added amounts of substrate is rather small. And when the potential is reduced to 0.0 V to -0.1 V, the sensitivity increases.

Keywords: polyaniline, carbon nanotubes, chronoamperometry, formaldehyde, acetaldehyde, propanal, formic acid.

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How to Cite

Kovalyshyn Y., Terenyak I., Goncha M., Reshetnyak O., Saldan I. ALDEHIDES OXIDATION ON PAN-CNT-ELECTRODE DECORATED WITH EXTRAFINE PLATINUM PARTICLES Proc. Shevchenko Sci. Soc. Chem. Sci. 2019 Vol. LVI. P. 112-121.

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