A nanocomposite consisting of porous graphitic carbon nitride nanosheets and oxidized multiwalled carbon nanotubes for simultaneous stripping voltammetric determination of cadmium(II), mercury(II), lead(II) and zinc(II)

• Published in: Mikrochimica acta (1966) 2019-02, Vol.186 (2), p.69-69, Article 69
• Main Authors: Ramalingam, Manikandan, Ponnusamy, Vinoth Kumar, Sangilimuthu, Sriman Narayanan
• Format: Article
• Language: English
• Subjects: Acidic oxides; Analytical Chemistry; Cadmium; Carbon; Carbon nitride; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Electrochemical impedance spectroscopy; Functional groups; Heavy metals; Lead; Mercury (metal); Mercury compounds; Microengineering; Morphology; Multi wall carbon nanotubes; Nanochemistry; Nanocomposites; Nanosheets; Nanotechnology; Organic chemistry; Original Paper; Oxidation; Reflectance; Reproducibility; Selectivity; Silver chloride; Spectrum analysis; Stripping; Transmission electron microscopy; Voltammetry; X-ray diffraction; Zinc
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-018-3178-7

A 3D nanocomposite consisting of porous graphitic carbon nitride nanosheets (p-g-C 3 N 4 -NSs) and oxidized multiwalled carbon nanotubes (O-MWCNTs) was prepared by simultaneous chemical oxidation of bulk g-C 3 N 4 and bulk MWCNTs. This one-step oxidation results in the formation of acidic functional groups on the basal surfaces of both g-C 3 N 4 and MWCNTs. Simultaneously, the O-MWCNTs are incorporated in-situ on the porous structure of p-g-C 3 N 4 . The acid functionalization and surface morphology of the nanocomposite were examined using attenuated total reflectance infrared spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy. The nanocomposite was used to modify a screen-printed electrode (SPE) which then was studied by using cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry. The modified SPE exhibits excellent sensitivity and selectivity towards the simultaneous detection of the heavy metal ions Cd(II), Hg(II), Pb(II) and Zn(II), typically at −0.78, +0.35, −0.5 and − 1.16 V (vs. Ag/AgCl). The detection limits (at S/N = 3) range between 8 and 60  n g L −1 under conditions of stripping analysis. The method was applied to the simultaneous detection of these ions in various (spiked) food samples. The results demonstrated the good accuracy and reproducibility of the method. Graphical abstract Schematic of a highly sensitive and selective electrochemical method for the simultaneous detection of four heavy metals. It is based on the use of a screen printed electrode (SPE) modified with 3D porous g-C 3 N 4 and O-MWCNTs, and of anodic stripping voltammetry.