In this work, new samples of PVA-TiO₂/Cu nanocomposites were prepared via the casting method. The prepared samples were examined using different analytical methods. An XRD analysis showed the semi-crystalline nature of the PVA polymer, as well as showing a decrease in the degree of the crystallinity of the PVA structure as a result of the addition of the mixed nanoparticles. TEM images indicate the spherical shape of the Cu NPs, with a size ranging from 2 to 22 nm, and the rectangular shape of the TiO₂ NPs, with a size ranging from 5 to 25 nm. It was evident via FTIR measurements that there were interactions between the functional groups of the PVA and the TiO₂/Cu NPs. The optical properties of the PVA nanocomposites were improved with an increase in the content of the TiO₂/Cu nanoparticles, as shown via a UV/Vis analysis. DSC curves showed an improvement in the thermal stability of the PVA-TiO₂/Cu nanocomposites after the embedding of the TiO₂/Cu nanoparticles. It was evident using impedance spectroscopy that the AC conductivity was improved by adding the TiO₂ and Cu nanoparticles to the polymeric matrix. The maximum AC conductivity was found at 1.60 wt.% of TiO₂/Cu nanoparticles in the PVA polymer, and this was 13.80 × 10⁻⁶ S/cm at room temperature. Relaxation occurred as a result of the charge carrier hopping between the localized state and the correlated barriers hopping model, describing the dominant mechanism, as presented in an electrical modulus analysis. These results indicate that the PVA-TiO₂/Cu nanocomposite samples can be used in energy storage capacitor applications and in the alternative separator-rechargeable lithium-ion battery industry.

In this article, the synthesis, optical, and electrical properties of composites consisting of polyethylene oxide (PEO), carboxymethyl cellulose (CMC), and titanium dioxide nanoparticles are examined. Flexible nanocomposite samples comprising PEO, CMC, and TiO₂ nanoparticles were produced swiftly via using the cast synthesis method. In addition, XRD and FT-IR analysis were performed in order to analyze the structures of the prepared samples. Our results demonstrate the PEO/CMC blend’s effectiveness in interacting with TiO₂ nanoparticles. The optical properties of the PEO/CMC and nanocomposite samples, such as the energy band gap, were studied using the UV/Vis optical absorbance. It was found that as TiO₂ NP weight fraction increases, the energy gap narrows. Moreover, TiO₂ nanoparticles with an average size of 16 nm were formed in spherical and rod shapes, according to a TEM image. The SEM images demonstrate how the distribution of TiO₂ NPs increased upon the surfaces of the prepared films. The antibacterial activity in the nanocomposites was shown to be enhanced by the TiO₂ NP concentrations. Finally, we proposed that PEO/CMC-0.8 wt. % TiO₂ nanocomposites with enhanced optical, electrical, and dielectric properties should be used in electrochemical devices.

Herein, we have successfully constructed a solid-state Z-scheme photosystem with enhanced light absorption capacity by combining the optoelectrical properties of AgNPs with those of the MoS₂/RGO/NiWO₄ (Ag-MRGON) heterostructure. The Ag-MRGON Z-scheme system demonstrates improved photo-electrochemical (PEC) water-splitting performance in terms of applied bias photon-to-current conversion efficiency (ABPE), which is 0.52%, and 17.3- and 4.3-times better than those of pristine MoS₂ and MoS₂/NiWO₄ photoanodes, respectively. The application of AgNPs as an optical property enhancer and RGO as an electron mediator improved the photocurrent density of Ag-MRGON to 3.5 mA/cm² and suppressed the charge recombination to attain the photostability of ∼2 h. Moreover, the photocurrent onset potential of the Ag-MRGON heterojunction (i.e., 0.61 V_RHE) is cathodically shifted compared to those of NiWO₄ (0.83 V_RHE), MoS₂ (0.80 V_RHE), and MoS₂/NiWO₄ heterojunction (0.73 V_RHE). The improved PEC water-splitting performance in terms of ABPE, photocurrent density, and onset potential is attributed to the facilitated charge transfer through the RGO mediator, the plasmonic effect of AgNPs, and the proper energy band alignments with the thermodynamic potentials of hydrogen and oxygen evolution.