Exploring electrical conductivity, antibacterial efficacy, and photocatalytic activity in nanosilver-decorated β-SiC/graphene nanocomposites

Abstract

A series of silver-doped β-SiC/graphene nanoparticles (NPs) were systematically synthesized via solid-state reactions, aiming to optimize electrical conductivity, heightening antibacterial efficacy, and enhancing photocatalytic activity. X-ray diffraction (XRD) analysis unequivocally revealed the crystalline nature of Ag-doped β-SiC, exhibiting a crystallite size ranging from 41 nm to 108 nm, as determined by various analytical methods. A discernible blue shift was observed in the Raman spectra, affirming successful silver doping in β-SiC concurrent with graphene formation. Fourier-transform infrared spectroscopy (FTIR) corroborated these structural observations. Additionally, UV–visible spectroscopic studies were conducted to precisely ascertain the band energy alignment, optimizing the optical performance of the synthesized samples. Remarkably, the electrical conductivity was augmented from 12% to 54%, primarily attributed to the graphene content, when compared to the silver contact. Furthermore, the antibacterial efficacy of silver-doped β-SiC was rigorously evaluated against two bacterial strains, Pseudomonas and S. aureus, using the disc diffusion method. Ag-doped β-SiC exhibited significant growth inhibition in the tested microorganisms. Notably, the combined application of 7% Ag-doped β-SiC and antibiotics demonstrated superior antibacterial activity compared with the individual components. The maximum bacterial inhibition zones for Pseudomonas and S. aureus, induced by a 20 μg applied concentration of 7% Ag-doped β-SiC, were measured at 29 mm and 31 mm, respectively. Furthermore, combining 7% Ag-doped β-SiC with Ciprofloxacin yielded substantial zones of inhibition at 46 mm and 48 mm for Pseudomonas and S. aureus, respectively. This study underscores the significant antibacterial properties of β-SiC-based nanoparticles doped with silver, suggesting their potential as promising candidates for therapeutic applications. Scanning electron microscopy (SEM) analysis of the Ag-doped β-SiC-graphene NPs revealed well-defined nanoparticles with a uniform size distribution, affirming the successful integration of silver doping into β-SiC and the formation of graphene, consequently enhancing the structural and morphological properties of the nanoparticles.