α-MoO3 nanobelts/CMC-PVA nanocomposites: hybrid materials for optoelectronic and dielectric applications

Polymer nanocomposites (PNCs) of Carboxymethyl cellulose (CMC)/Polyvinyl alcohol (PVA) incorporated with various quantities of MoO3 nanobelts were prepared via a casting technique. The XRD patterns depicted the orthorhombic structure of MoO3 NBs with an average crystallite size of 75.82 nm, and the crystallinity degree of nanocomposite samples significantly decreased after loading MoO3 nanobelts. The TEM image shows a nanobelt-like morphology of MoO3 powder. The ATR-FTIR spectra of the prepared PNCs established the strong interaction between CMC/PVA polymer blend and MoO3 NBs. From the spectra of the UV–Vis-NIR technique, the optical parameters of the CMC/PVA matrix could be adjusted by the NBs addition, where the optical band gap (direct and indirect) and refractive index were calculated and discussed. The dielectric dispersion and relaxation processes of CMC/PVA/MoO3 were tested over the frequency range from 0.1 Hz to 20 MHz at RT. Improved values of ε′ and ε″ for the films after adding MoO3 NBs are due to the increment in the effective parallel ordering of dipoles, resulting in increased dielectric polarization. The conductivity was enhanced after loading the MoO3 NBs owing to the improvement in the charge carriers. The frequency exponent (s) value was used to identify the conduction model in the prepared samples as a correlated barrier hopping one. These results are predicted to have a significant impact on a wide range of electric and optoelectronic applications including separators in batteries, flexible capacitors, and energy storage devices.