rGO Blended PbS:Ag Nanoparticles for Rhodamine B Dye Degradation and Growth Inhibition of S. aureus and E. coli Bacterial Strains

Abstract

Photocatalytic and antibacterial properties of PbS:Ag (PA) and rGO-blended PbS:Ag (rPA) nanoparticles (NPs) have been compared and reported in this paper. Chemical precipitation and one-pot synthesis methods were used to synthesize NPs of PA and rPA. X-ray diffraction (XRD) studies reveal a cubic crystal structure for both samples, with preferential growth along the (200) plane. Crystallite sizes were 55 and 41 nm for PA and rPA, respectively. Scanning electron microscopy (SEM) images of rPA revealed clustered grains. Both samples exhibited Pb–S bands in Fourier-transform infrared spectroscopy (FTIR) studies. Near band edge emissions occurred at 504, 520, 539 and 595 nm for both PA and rPA. The inclusion of rGO into PA led to lattice misfit, crystal growth disorders, and increased grain boundary scattering. This series of structural disruptions contributed to a reduction in the photoluminescence (PL) intensity for the rPA composite. A higher degradation efficiency of 95.4% was achieved for the rPA catalyst against Rhodamine B dye under visible light. The antibacterial activity of PA is increased with rGO inclusion due to increased generation of reactive oxygen species (ROS).