Synthesis and characterization of copper oxide/titanium dioxide-enhanced polymer nanocomposites for optoelectronic devices

Copper oxide/titanium dioxide nanoparticles (CuO/TiO₂ NP) were synthesized by precipitation. The polymer nanocomposites (PNCs) were prepared using the casting technique, incorporating Hydroxypropyl methylcellulose (HPMC) and polyethylene oxide (PEO) with varying concentrations of CuO/TiO₂ nanoparticles: 2, 4, and 8 wt%. X-ray diffraction (XRD) analysis demonstrated a reduction in the crystallinity of the PNCs, highlighting changes in their microcrystalline properties. FT-IR spectroscopy confirmed the successful formation of the nanocomposites and identified the functional groups present. The optical properties were examined with a UV–Vis spectrophotometer, and each film’s absorbance coefficient was calculated. Incorporating 8% CuO/TiO₂ into the HPMC/PEO matrix reduced the bandgap energies (E_gd and E_gin) of pure HPMC/PEO to 3.06 eV and 0.63 eV, respectively. The Urbach energy (Eu) values increased from 0.225 ± 0.022 eV to 0.423 ± 0.052 eV as the CuO/TiO₂ concentration increased from 0 to 8 wt%. Adding CuO/TiO₂ NP to the HPMC/PEO matrix significantly improved charge conduction, as evidenced by enhanced conductivity results in the filled samples. With increasing frequency, both the dielectric constant (ε′) and dielectric loss (ε″) decreased. Impedance studies revealed that increasing the CuO/TiO₂ concentration from 0 to 8 wt% reduced the bulk resistance (Rb) from 2.48 × 10⁷ Ω to 1.50 × 10⁶ Ω, enhancing ionic conductivity and confirming the suitability of the HPMC/PEO–CuO/TiO₂ nanocomposite for microelectronic applications. Overall, the experimental results suggest that the synthesized nanocomposites hold great promise for use in optoelectronic devices and capacitive energy storage systems.