Catharanthus roseus leaf extract mediated Ag-MgO nanocatalyst for photocatalytic degradation of Congo red dye and their antibacterial activity

A simple and cost-effective green synthesis approach was used for the manufacture of MgO and Ag–MgO nanocomposites using Catharanthus roseus leaf extract and its photocatalytic ability against congo red (CR) dye was investigated. UV–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), X-ray difraction (XRD), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) were used to examine the synthesised MgO NPs and Ag-MgO nanocomposite. The XRD pattern of MgO nanoparticles and Ag-MgO nanocomposites reveals fcc structure. Spherical shaped NPs were confirmed using SEM and TEM analysis. The EDX profile confirmed the presence of Mg, Ag, and O elements. The existence of functional group responsible for stabilizing Ag-MgO nanocomposite was verified using FTIR analysis. According to XPS spectra, valencies and binding energies of MgO and Ag elements were found in the as-prepared Ag-MgO nanocomposites. Ag-MgO NCs degraded congo red (CR) dye faster than pure MgO NPS under sunlight irradiation than pure MgO NPs. The effect of dopant concentration on lowering recombination between electrons and holes was linked to increased photocatalytic activity of Ag-MgO NCs. Antibacterial results show good antibacterial activity against gram-positive (S. aureus) and gram-negative (E-Coli) microbial pathogens. These findings revealed the environmental remediation potential of Ag-doped MgO NPs.