Structural, morphological, and optical properties of SiC/PVP nanocomposite materials by changing the SiC concentration in PVP

Abstract

Silicon carbide (SiC) nanotubes with a one-dimensional structure were successfully synthesized via the carbothermal method at 1800 °C. SEM results revealed a hollow interior and rough surface morphology. These SiC nanotubes were incorporated into a polyvinylpyrrolidone (PVP) matrix to produce SiC/PVP composite materials with different filler concentrations (1–5 wt%). XRD analysis confirmed the presence of the cubic 3C–SiC phase. SiC nanotubes were incorporated into a PVP polymer matrix at concentrations of 1, 2, 3, and 5 wt% SiC. Scanning electron microscopy (SEM) images revealed the morphology of the nanotubes of pure SiC. Energy-dispersive X-ray spectroscopy (EDS) and elemental mapping showed a non-uniform SiC distribution across the polymer, with the most uniform dispersion occurring at 3 wt%. X-ray diffraction (XRD) results indicated a decrease in crystallite size as SiC content increased, with the smallest crystallite size (11.86 nm) occurring at 3 wt% SiC/PVP. The microstrain and dislocation density also exhibited a similar trend, increasing from 1 wt% (0.00587) to 3 wt% (0.00698) and then decreasing at 5 wt% SiC/PVP (0.00271). Ultraviolet-Visible (UV-Vis) spectroscopy revealed a band gap reduction from 5.62 eV at 1 wt% to 5.51 eV at 3 wt% SiC/PVP, with a slight increase to 5.70 eV at 5 wt% SiC/PVP, indicating the most favorable optical properties at 3 wt% SiC/PVP composite materials. Fourier-transform infrared (FTIR) spectroscopy confirmed the physical interaction between SiC and PVP, characteristic Si–C stretching bands at 700–1000 cm⁻¹, as well as the interaction of PVP carbonyl (CO) and C–N groups with Si–O/–OH groups on the SiC surface without any covalent bonding formation. The 3 wt% SiC/PVP composite demonstrated optimal dispersion, crystallite refinement, and optical properties, indicating its potential as the optimal loading concentration for electronics and semiconductors, optical devices, and energy storage and conversion, making it an ideal material for advanced technological uses.