Publication details

Generation of graphite nanomaterials from pencil leads with the aid of a 3D positioning sparking device: Application to the voltammetric determination of nitroaromatic explosives

Authors

TRACHIOTI Maria HEMZAL Dušan HRBÁČ Jan PRODROMIDIS Mamas I

Type Article in Periodical
Magazine / Source Sensors and Actuators B: Chemical
MU Faculty or unit

Faculty of Science

Citation
Web Full Text
Doi http://dx.doi.org/10.1016/j.snb.2020.127871
Keywords Electric discharge Carbon nanomaterials; Sparking ; 2.4.6-trinitrotoluene ; Screen-printed electrodes
Description We report on facile generation of graphite nanomaterials (GNMs) with advanced electro catalytic propertiesthrough a direct electric discharge process between pencil leads and graphite screen-printed electrodes (SPEs)at ambient conditions at 1.2 kV. Various commercially available pencil leads of different degrees of hardnesswere examined. Sparked GNM-SPEs were characterized by Raman spectroscopy, SEM, CV, and EIS. Taking ascriterion the highest response to the electro-reduction of nitro group of 2,4,6-trinitrotoluene (TNT) at-0.3 Vat deoxygenated solutions, Castell 9000 (2B) pencil was selected as optimum. GNM-SPEs exhibited a linearresponse over the concentration range 1-100 ppb TNT, while the limit of detection (LOD) based on the 3sigma/mcriterion was calculated 0.44 ppb. The interference effect of other nitro-aromatic explosives and maskingcompounds, which are used to hinder the detection of TNT, was extensively investigated. The determination ofTNT was also achieved by measuring the oxidation of the electrochemically generated hydroxylamine groups. Inthis format, each measurement was conducted with a new electrode polarized at-0.275 V for 2 min. At the costof a slightly increased time of analysis, the anodic determination of TNT offered increased selectivity, applic-ability in non-deoxygenated solutions, linear response over the concentration range 1-50 ppb TNT and anLOD of 0.25 ppb. GNM-SPEs were successfully applied to the determination of TNT in spiked drinking watersamples. Recovery was 101-108 %.