Many research papers are currently being written about various methodologies for the green synthesis of ZnO nanoparticles. In this study, ZnO nanoparticles were prepared by green synthesis method using baker’s yeast ( Saccharomyces cerevisiae). The characterization of the produced ZnO nanoparticles involved the utilization of XRD, FTIR, SEM, and TEM. The investigation involved the assessment of the antimicrobial potential and photocatalytic degradation efficacy of the synthesized materials through the utilization of Eriochrome Black T (EBT). The results indicate that the ZnO nanoparticles exhibit a spherical morphology, exhibiting diameters ranging from 13.0 to 20.0nm, with an average particle size of 15.0nm. The antimicrobial efficacy against (S. aureus) gram-positive and (E. coli) gram-negative bacteria was tested through the conduction of zone of inhibition (ZOI) and minimum inhibitory concentration (MIC) tests. This research focused on the study of the photocatalytic-degradation of EBT in the presence of ultraviolet light. The experiments focused on the impact of various factors, such as pH levels, initial EBT concentration, and nanocatalyst dosage, on the observed photocatalytic efficiency. In the in vitro ZOI and MIC results assay, it was observed that ZnO nanoparticles (NPs) exhibited greater efficacy against gram-positive S. aureus, with a ZOI measuring 23.1 mm and a MIC of 0.625 μg/ml. In contrast, the effectiveness of ZnO-NPs against gram-negative E. coli was comparatively lower, as indicated by a ZOI of 17.0 mm and a MIC of 1.250μg/ml. The greatest EBT elimination, which achieved 83.0% in equilibrium, was found employing 20.0mg of ZnO NPs at pH 3.0, according to the photocatalytic activity results. The synthetic ZnO NPs are powerful antibacterial agents that are effective against tested bacteria and may be used in the treatment of wastewater.

Water scarcity is now a serious global issue resulting from population growth, water decrease, and pollution. Traditional wastewater treatment plants are insufficient and cannot meet the basic standards of water quality at reasonable cost or processing time. In this paper we report the preparation, characterization and multiple applications of an efficient photocatalytic nanocomposite (Co_xNi_1−xFe₂O₄; x = 0.9/SiO₂/TiO₂/C-dots) synthesized by a layer-by-layer method. Then, the photocatalytic capabilities of the synthesized nanocomposite were extensively-studied against aqueous solutions of chloramine-T trihydrate. In addition, reaction kinetics, degradation mechanism and various parameters affecting the photocatalytic efficiency (nanocomposite dose, chloramine-T initial concentration, and reaction pH) were analyzed in detail. Further, the antimicrobial activities of the prepared nanocomposite were tested and the effect of UV-activation on the antimicrobial abilities of the prepared nanocomposite was analyzed. Finally, a comparison between the antimicrobial abilities of the current nanocomposite and our previously-reported nanocomposite (Co_xNi_1−xFe₂O₄; x = 0.9/SiO₂/TiO₂) had been carried out. Our results revealed that the prepared nanocomposite possessed a high degree of crystallinity, confirmed by XRD, while UV–Vis. recorded an absorption peak at 299 nm. In addition, the prepared nanocomposite possessed BET-surface area of (28.29 ± 0.19 m²/g) with narrow pore size distribution. Moreover, it had semi-spherical morphology, high-purity and an average particle size of (19.0 nm). The photocatalytic degradation efficiency was inversely-proportional to chloramine-T initial concentration and directly proportional to the photocatalyst dose. In addition, basic medium (pH 9) was the best suited for chloramine-T degradation. Moreover, UV-irradiation improved the antimicrobial abilities of the prepared nanocomposite against E. coli, B. cereus, and C. tropicalis after 60 min. The observed antimicrobial abilities (high ZOI, low MIC and more efficient antibiofilm capabilities) were unique compared to our previously-reported nanocomposite. Our work offers significant insights into more efficient water treatment and fosters the ongoing efforts looking at how pollutants degrade the water supply and the disinfection of water-borne pathogenic microorganisms.

In this paper, we report a layer-by-layer approach for the preparation of a concentric recyclable composite (Co _x Ni _1−x Fe ₂ O ₄ /SiO ₂ /TiO ₂ ; x = 0.9) designed for wastewater treatment.

This study reports the antibacterial and antibiofilm activities of Magnesium ferrite nanoparticles (MgFe₂O₄) against gram-positive and gram-negative bacteria. The photocatalytic degradation of Carbol Fuchsin (CF) dye (a class of dyestuffs that are resistant to biodegradation) under the influence of UV-light irradiation is also studied. The crystalline magnesium ferrite (MgFe₂O₄) nanoparticles were synthesized using the co-precipitation method. The morphology of the resulting nanocomposite was examined using scanning electron microscopy (SEM), while transmission electron microscopy (TEM) was employed for further characterization of particle morphology and size. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were utilized to analyze the crystalline structure, chemical composition, and surface area, respectively. Optical properties were evaluated using UV–Vis spectroscopy. The UV-assisted photocatalytic performance of MgFe₂O₄ nanoparticles was assessed by studying the decolorization of Carbol fuchsin (CF) azo dye. The crystallite size of the MgFe₂O₄ nanoparticles at the (311) plane, the most prominent peak, was determined to be 28.5 nm. The photocatalytic degradation of 10 ppm CF using 15 mg of MgFe₂O₄ nanoparticles resulted in a significant 96% reduction after 135 min at ambient temperature (25 °C) and a pH value of 9. Additionally, MgFe₂O₄ nanoparticles exhibited potent antibacterial activity against E. coli and S. aureus in a dose dependent manner with maximum utilized concentration of 30 µg/ml. Specifically, MgFe₂O₄ nanoparticles demonstrated substantial antibacterial activity via disk diffusion and microbroth dilution tests with zones of inhibition and minimum inhibitory concentrations (MIC) for E. coli (26.0 mm, 1.25 µg/ml) and S. aureus (23.0 mm, 2.5 µg/ml), respectively. Moreover, 10.0 µg/ml of MgFe₂O₄ nanoparticles elicited marked percent reduction in biofilm formation by E. coli (89%) followed by S. aureus (78.5%) after treatment. In conclusion, MgFe₂O₄ nanoparticles demonstrated efficient dye removal capabilities along with significant antimicrobial and antibiofilm activity against gram-positive and gram-negative bacterial strains suggesting their potential as promising antimicrobial and detoxifying agents.