Role of non-covalent interactions at the oxidation of 2,5-di-Me-pyrazine-di-N-oxide at glassy carbon, single-walled and multi-walled carbon nanotube paper electrodes

Electrochemical and quantum chemical studies of peculiarities of 2,5-di-Me-pyrazine-di-N-oxide oxidation in the presence of methanol at single-walled and multi-walled carbon nanotube paper electrodes

“…Materials and experimental techniques for obtaining cyclic voltammograms, EPR spectra during electrolysis at controlled potentials and dependence of the differential capacitance of the electrical double layer on potentials were described in previous studies. 18,20 The quantum chemical modeling technique was described in detail in our previous work. 20 1) was chosen to simulate single-walled conductive (10,10) CNTs because in our previous work 20 it was shown to be a suitable model.…”

“…18,20 The quantum chemical modeling technique was described in detail in our previous work. 20 1) was chosen to simulate single-walled conductive (10,10) CNTs because in our previous work 20 it was shown to be a suitable model. For the modeling of the adsorption of CH 3 OH, CH 3 COOH and H 2 O, on the surface of CNTs, the functional wB97XD 21 was used in the software package GAUSSIAN-09.…”

“…Oxidation of Pyr 1 at MWCNT and SWCNT paper electrodes in 0.1 M Bu 4 NClO 4 solution in MeCN occurs at a potential of 1.78 V, 20 that is, at higher by 220 mV as compared with oxidation at the GC electrode. The process is irreversible and not diffusion-controlled.…”

“…In the absence of MeOH. The oxidation of Pyr 1 at GC, SWCNT and MWCNT paper electrodes was studied in a previous study 20 in 0.1 M Bu 4 NClO 4 solution in MeCN with the use of the methods of quantum-chemical modeling, cyclic voltammetry, EPR-electrolysis and differential capacitance. It was shown 20 that the process of Pyr 1 oxidation at the GC electrode (E ox = 1.56 V) in 0.1 M Bu 4 NClO 4 solution in MeCN is one-electron, irreversible, and diffusion-controlled and the charge transfer is followed by an irreversible chemical reaction (an EC mechanism) with a rate constant equal to 0.6 s À1 .…”

“…It was noted [16][17][18][19] that in the absence of the substrate the oxidation current of phenazine-di-N-oxide, 2,3,5,6-tetra-Me-pyrazine-di-Noxide, at SWCNT or MWCNT paper electrodes is by several times higher than the oxidation current of the ferrocene (Fc) reference. Quantum chemical modeling of the adsorption energies of Pyr 1 , Fc and MeCN both on the CNT surface and in grooves between two CNTs using the cluster model simulating the surface of conducting and non-conducting carbon nanotubes 20 can explain this effect.…”