Conjugated Polymer /Multi Wall Carbon Nanotubes Composite Characterisation for Application in Volatile Organic Compounds Sensors

Highlight

·      Polyimidazole and multi-walled carbon nanotubes nanocomposite film were synthesised by mixing them in 1:1 ratio.

·      FTIR revealed an increase in the intensity of peaks in the control sample of the composite

·      Raman spectroscopy shows D-band peaks which confirmed the mixing of the two substances.

·      Current voltammetry measurements show a reversible wave that is the typical behaviour of conductive surfaces in the presence of the redox couple

·      Impedance measurements reveal a higher electron transfer rate in the redox probe and good electrical behaviour.

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Graphical Abstract

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Abstract

Polyimidazole multi-walled carbon nanotubes (MWCNTs) nanocomposite film were synthesised by chemical oxidation of imidazole monomer and addition of MWCNTs to the conductive polymer (CP) solution in 1:1 ratio. Chemical characterisation using FTIR where there is an increased in intensity of peaks in the control sample from 2823 and 2937 cm-1 to 2833 and 2947 cm-1 in Plm/MWCNTs composite respectively and Raman spectroscopy in which Plm/MWCNTs shows the so-called D-band (attributed to disordered sp2 and non-sp2 carbon defects in graphitic sheets) and G-band (attributed to the C–C vibration with the sp2 hybridized orbital in graphene structures) peaks at 1355 cm-1 and 1593 cm-1, but chemical analysis confirmed the mixing of the polymer and the MWCNTs. Electrical measurements using current voltammetry (CV) that shows a reversible wave that is the typical behavior of conductive surfaces in the presence of the redox couple and Impedance measurements in which the largest semicircle was obtained with Plm/CNTs film that corresponds to a film resistance on the real axis of 350 MΩ which is an indication of a higher electron transfer rate in the redox probe and good electrical behaviour. The overall results have shown that the composite has a significant electrical conductivity and can be applied in sensing volatile organic compounds in the environment.

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