Enhancing the optical, electrical, dielectric properties and antimicrobial activity of chitosan/gelatin incorporated with Co-doped ZnO nanoparticles: Nanocomposites for use in energy storage and food packaging

Abstract

The solution casting method was utilized to produce a brand of new nanocomposites made of chitosan (Cs), gelatin (Ge), and co-doped ZnO nanoparticles (NPs). The physicochemical characteristics of these nanocomposites were examined using a variety of methods. The doped samples' XRD patterns clearly demonstrated changes in the structural features of the Cs/Ge host polymer, with the widening of the peak at 2θ = 20.31 becoming more prominent as Co-doped ZnO NPs concentration increased. Tauc's relation was utilized to describe the direct and indirect bandgap energies using UV–Vis analysis. By including 3.5 wt% of Co-doped ZnO NPs, the optical energy gap direct and indirect of pure Cs/Ge was reduced from 5.22 to 4.92 eV to 4.90 and 4.42 eV, respectively. Co-doped ZnO NPs reinforcing has a significant impact on the in ac conductivity, dielectric constant and loss tangent values. An ionic conductivity of 1.089 × 10−7 S/cm at Cs/Ge-3.5 wt% Co-doped ZnO NPs was observed. The nanocomposites' antimicrobial effect on bacteria and fungi was tested. The adding of 3.5 %Co-doped ZnO NPs improved the activity against S. aureus (22 mm), E. coli (13 mm), A. niger (29 mm), and C. albicans (27 mm) despite the fact that the investigated pure mix had no effect on the microbiological strains. The current research's remarkable findings in terms of optical, dielectric, electrical, and antimicrobial effects indicate that Cs/Ge-coated ZnO film will have significant uses in both food packaging and energy storage devices.