Green-synthesized CdS nanoparticles using Bauhinia: Optical, structural, and antibacterial properties

This study reports the green synthesis of CdS nanoparticles (NPs) using Bauhinia leaves extract as a capping and stabilizing agent. XRD analysis confirms cubic nanoparticle formation, with a significant size variation. FESEM images and EDX spectra validate NP formation and elemental composition. FTIR and Raman spectroscopy reveal structural insights, showcasing the influence of Bauhinia leaves extract. Optical band gap energies, estimated via UV-Visible spectroscopy, increase from 2.30 to 2.45 eV with extract addition, with optical parameters systematically demonstrated. Antibacterial activity against Enterobacter cloacae , Chromobacterium violaceum, Enterococcus faecalis, Escherichia fergusonii and Escherichia coli is also assessed. This study reveals that the inhibitory action has been found to be increased with the rise in the amount of leaf extract and the combined action of CdS and leaf extracts enhances the capability of antimicrobial action of the NPs. Density functional theory (DFT) calculations provide qualitative insight into the intrinsic electronic structure and direct-gap nature of the CdS phase and help to understand the electronic structure of synthesized CdS nanoparticles. This study highlights the potential of biocompatible materials in synthesizing CdS NPs for optoelectronic applications.