Characterization and Bioactivity of Piper chaudocanum L. Extract-Doped ZnO Nanoparticles Biosynthesized by Co-Precipitation Method.

Green synthesis and nanomaterials have been the current trends in biomedical materials. In this study, Piper chaudocanum L. leaf extract-doped ZnO nanoparticles (PLE-doped ZnO NPs), a novel nanomaterial, were studied including the synthesis process, and the biomedical activity was evaluated. PLE-doped ZnO NPs were synthesized by the co-precipitation method, with differences in the synthesis procedures and dosages of the extract. The X-ray diffraction, Fourier transform infrared, scanning electron microscopy, energy dispersive X-ray spectroscopy, Brunauer-Emmett-Teller, ultraviolet-visible diffuse reflectance spectroscopy, and photoluminescence spectrum analysis results showed that the biosynthesized PLE-doped ZnO NPs were pure and in a hexagonal wurtzite phase. The PLE-doped NPs were synthesized by adding the extract to the zinc acetate solution before adjusting the pH and exhibited the smallest size (ZPS50 was 22 nm), the richest in the surface organic functional groups and the best optical activity. The highest antibacterial activity against P. aeruginosa and S. aureus was observed at 100 µg/mL of ZPS50 NPs, and the inhibition zone reached 42 and 39 nm, respectively. Moreover, ZPS50 NPs showed a moderate effectiveness against KB cancer cells with an IC50 value of 43.53 ± 2.98 µg/mL. This present study's results suggested that ZPS50 NPs could be a promising nanomaterial in developing drugs for treating human epithelial carcinoma cells and infectious illnesses.

Synthesis, characterization of novel ZnO/CuO nanoparticles, and the applications in photocatalytic performance for rhodamine B dye degradation.

Photocatalytic deg radation of environmental pollutants is being up to date for the treatment of contaminated water. In the present study, ZnO/CuO nanomaterials were successfully fabricated by a simple sol-gel method and investigate the photo-degradation of rhodamine B (RhB). The synthesized ZnO/CuO nanoparticles were characterized by X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS), thermal analysis (TGA), surface charge, and Fourier transform infrared spectroscopy (FTIR). The photo-degradation of the dye RhB was followed spectroscopically. The overall composition of ZnO/CuO material was found to be wurtzite phase, with particle size of 30 nm, and the Vis light absorption increased with an increase of Cu content. The ZnO/CuO nanomaterials were highly active leading to a photo-degradation of 10 ppm RhB reaching 98% within 180 min at 0.1 g/L catalyst dosage. The change in surface charge after degradation evaluated by ζ potential measurements and the differences in functional vibration group monitored by Fourier transform infrared spectroscopy (FTIR) indicates that the RhB adsorption on the Zn45Cu surface was insignificant. And scavenging experiments demonstrate that the RhB degradation by ZnO/CuO nanomaterials involves to some degree hydroxyl radicals.