Solar light driven green synthesis of ZnO nanoparticles for effective photodecomposition of basic fuchsine dye and its antimicrobial properties
摘要
In this study, ZnO Nano-particles (ZnO NPs) were synthesized by green chemistry using an aqueous extract of Salvia Verbenaca leaves (S. Verbenaca) for the first time. The as-prepared ZnO NPs were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), UV–Vis spectroscopy, FT-IR spectroscopy, thermo gravimetry (TG) and BET analysis. The diffractogram confirmed the hexagonal structure of ZnO NPs with crystallite size of 50 nm, while the SEM image revealed that the particles are agglomerated with a spherical shape. The optical properties of ZnO NPs were studied and the band gap (3.01 eV) was determined from the diffuse reflectance. The FT-IR spectra indicated the presence of biomolecules from the plant extract acting as capping agent. The TG analysis indicated the formation of ZnO NPs and BET analysis, confirmed the formation of a mesoporous NPs. The photocatalytic activity of ZnO NPs was evaluated through the degradation of Basic Fuchsine (BF), a hazardous dye under solar irradiation. This study was undertaken by varying the physical parameters namely the initial concentration of the dye (Co: 5–50 ppm), the catalyst dose (10–45 mg) the extract dose (5–15 g/L). The results show that the best abatement was obtained for the initial concentration of 10 mg/L and 45 mg of ZnO NPs. More interestingly, we also prepared the hetero-junction (90% ZnO–10% CuO) and a degradation yield of 90% was reached after 90 min under sunlight. The stability test shows that the product maintains its effectiveness after 4 successive cycles as checked by FT-IR spectroscopy. The oxidation state of Zn was investigated by XPS analysis and the elements Zn and O are indicated by the surface survey spectrum. The photoluminescence shows strong emission at 528 nm, associated to surface defects on the nanoparticles. Additionally, ZnO NPs exhibited potent antibacterial activity against both Gram (positive–negative) bacteria, with a higher effectiveness observed for Gram-positive strains. This work highlights the potential of S. Verbenaca-mediated ZnO NPs as an eco-friendly solution for environmental remediation and antimicrobial applications.