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Nanotechnology has emerged as a promising multidisciplinary field. It has shown several applications including diagnostics, imaging and structural design. Nanoparticles can be synthesized via chemical and physical approaches, carrying many threats to the ecosystem. To overcome these threats, sustainable routes for the synthesis of nanoparticles were implemented. Green synthesis is the most fascinating and attractive alternative to chemical synthesis as it offers more advantages. Nontoxic and eco-friendly secondary metabolites from plants are used as reducing and capping agents. This process is comparatively simple and cost-effective. A gold salt is simply reduced by biomolecules (phenols, alkaloids, proteins, etc.) present in the extracts of these plants. In this review, we have emphasized the synthesis and antimicrobial potential of gold nanoparticles using various plant extracts and their proposed mechanisms. Abbreviation: Au: aurum; gold; DLS: dynamic light scattering; EDAX: energydispersive X-ray analysis; EDS: energy-dispersive spectroscopy; FTIR: Fourier transform infrared spectroscopy; HRTEM: highresolution transmission electron microscopy; NPs: nanoparticles; UV–VIS: ultra violet-visible spectroscopy; SEM: scanning electron microscopy; XRD: X-ray Diffraction [ABSTRACT FROM PUBLISHER]

In this work, tri-phase direct dual S-scheme ZnO–V 2 O 5 –WO 3 heterostructured nanocomposite and pure ZnO, V 2 O 5 , and WO 3 nanoparticles were synthesized by using a facile co-precipitation approach to investigate antibacterial and photocatalytic characteristics of the grown nanocomposite. The physical properties of as-synthesized products were examined by employing characterization techniques such as Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman, Fourier transform infrared spectroscopy (FTIR), and UV–vis spectroscopy. The XRD results confirmed the formation of pristine ZnO, V 2 O 5 , WO 3 nanoparticles and the existence of diffraction peaks related to hexagonal phase ZnO, orthorhombic V 2 O 5 , and monoclinic phase of WO 3 in ZnO–V 2 O 5 –WO 3 nanocomposite. The variation in structural parameters was studied by SSP, Scherrer plot, and W–H models. The energy bandgap of nanocomposite (2.63 eV) was calculated from UV–vis spectroscopy, which indicated the usability as a photocatalyst under direct sunlight. FTIR and Raman's spectra also supported the formation of the ZnO–V 2 O 5 –WO 3 nanocomposite. Spherical and roughly hexagonal morphology were seen in SEM images. EDX analysis has confirmed the existence of Zn, V, W, and O in the nanocomposite. The antibacterial test against Klebsiella pneumonia, Staphylococcus aureus , Proteus Vulgaris, and Pseudomonas aeruginosa bacteria showed higher activity. The photocatalytic performance of the ZnO–V 2 O 5 –WO 3 nanocomposite (99.8%) was the highest against methylene blue (MB) as compared to pure ZnO (78.8%), V 2 O 5 (85.8%), and WO 3 (80.0%) under natural sunlight. The degradation efficiency of ZnO–V 2 O 5 –WO 3 against cresol red (CR), rhodamine-B (RhB), methyl orange (MO), safranin-O (SO), and methyl red (MR) dyes was 67.0%, 86.6%, 98.0%, 76.8%, and 99.0%, respectively, under direct sunlight in 80 min. Different schematic models are designed to illustrate the photocatalytic reaction mechanism, whereas the separation of charge carriers and enhanced photocatalytic performance can be efficiently explained by S-scheme. [Display omitted] • Facile synthesis of tri-phase direct dual S-scheme ZnO–V 2 O 5 -WO 3 heterostructured NC and pure ZnO, V 2 O 5 , and WO 3 NPs. • SEM, EDX, XRD, Raman, FTIR, and UV–vis was carried out. • The photocatalytic performance was tested against MB, CR, RhB, MO, SO, and MR dyes. • S-scheme is more efficient than other schemes for enhancing photocatalytic activity. • The antibacterial test against different bacteria strain was performed. [ABSTRACT FROM AUTHOR]