Spectroscopic studies, molecular structure optimization and investigation of structural and electrical properties of novel and biodegradable Chitosan-GO polymer nanocomposites

This article covers the molecular structure optimization and spectroscopic studies, such as Raman, UV–Vis absorption and FTIR, carried out for novel, biodegradable and biocompatible chitosan-graphene oxide (CS-GO) polymer nanocomposites (PNCs), which were synthesized by using simple blending technique followed by ultrasonification treatment. In addition, the structural and electrical properties have also been investigated. Under molecular structure optimization, the structural geometry, electronic structure (HOMO and LUMO) and potential distribution have been computed. X-ray diffraction of PNCs reveals that the crystallized phase of GO dominates over the CS giving modification in crystallite size and presence of micro-strain. FTIR and Raman spectroscopic studies have been carried out to confirm the proper formation of PNCs and presence of functional group in the composites. The surface morphology has been studied with the help of FESEM to confirm proper dispersion of GO sheets. Optical absorption edge and band gap analyzed from UV–Vis analysis reveal the semiconducting nature of PNCs. In addition, the optical band gap is tuned by varying the content of GO in PNCs. This tuning in band gap has also been supported by XRD and computational results. The dielectric constant and dc conductivity are found increased with increasing content of GO in PNCs. Additionally, the I–V characteristics of PNCs shows Ohmic type conduction with rising in current due to incorporation of GO. In view of the results achieved, the usage of CS-GO PNC is suitable for future development of optical and Gas sensors and UV-detectors, and therefore, such composite may be proven as a potential and suitable candidate for the optoelectronic or electrical devices operating at high frequencies.