Effect of MWCNTs and aluminum amount on tuning the optical and electrical properties of PVA/PVP/PEG/ZnCo_2-xAl_xO₄ composites

Novel and low-cost blended polymers were created based on polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG) as host polymer matrix doped with nano ZnCo_2-xAl_xO₄ samples with and without multi-walled carbon nanotubes (MWCNTs) via sol–gel and casting procedures. The structure and morphology of the studied samples were explored. Compared to an undoped PVA/PVP/PEG blend, a doped blend is better at absorbing visible light. Doped blend with 10% Al in the absence of MWCNTs showed the maximum absorbance, but the blend doped with MWCNTs and 20% Al nanofiller had the highest absorbance. The blend's reflectivity changed depending on the quantity of Al in ZnCo_2-xAl_xO_{4 (}with and without MWCNTs). The lowest direct and indirect optical bandgap energies (5.16 and 4.65) eV were obtained as the blend loaded with filler contained 20% Al and MWCNTs. Blend ed polymer with 20% Al and MWCNTs exhibited the highest refractive index value. The optical dielectric constant, optical conductivity, nonlinear optical parameters and fluorescence spectra were affected by the amount of Al and the existence of MWCNTs in the blends. The blend displayed a significant raise in ac conductivity when loaded with nanofiller included 20% Al and MWCNTs. The maximum energy density value can be obtained as the blend doped with filler contained only 20% Al. Every blend had one relaxation time, with the exception of the blend doped with ZnCo_1.8Al_0.2O₄ (containing MWCNTs), displayed two relaxation times. The dopant affects the capacitance of the different blends. PVA/PVP/PEG/ZnCo_2-xAl_xO₄ blends (with and without MWCNTs) have been considered promising nanocomposites for flexible optoelectronic and energy storage applications.