Study of Zn-Astrakanite/CuO/ZnO Nanocomposite Using Tribulus terrestris Aqueous Extract, and Their Structural, Optical, Morphological, Dielectric, and Bacterial Properties.

Zn-astrakanite/CuO/ZnO nanocomposite was prepared using environmentally friendly and biogenically derived approaches through nanoengineering. Tribulus terrestris plant extract was used in this study to synthesize the Zn-astrakanite/CuO/ZnO nanocomposite. For the first time, the formation of a Zn-substituted astrakanite structure was achieved using a green synthesis method guided by the reducing, capping, and chelating agents present in the Tribulus terrestris plant extract. By using Ultraviolet visible (UV-vis) spectroscopy, we observe a characteristic peak at 376 nm that indicates the presence of ZnO nanoparticles, and in addition, the appearance of green color confirmed the presence of CuO nanoparticles in colloidal solutions. An analysis of Rietveld refined powder X-ray diffraction (PXRD) provides insight into the novel crystalline structure of Zn-astrakanite. It was found from the Rietveld refinement results that the synthesized nanocomposite composed of CuO, Zn-astrakanite, and ZnO crystalline phases with compositions 56.26%, 31.49%, and 12.26%, respectively. The green color appearance of the synthesized nanocomposite in colloidal solution was due to the presence of CuO nanoparticles as a major composition and surface plasmon resonance (SPR) characteristic. As revealed by scanning electron microscopy (SEM) analysis, nanoparticles have blade-like morphologies due to ZnO and some randomly shaped crystallites. Fourier transform infrared spectroscopy (FTIR) analysis provides functional information about the synthesized compound, and we detected CuO and ZnO nanocomposites by observing the metal oxide fingerprint regions at 523 cm-1 and 472 cm-1. The synthesized nanocomposites were reported to have good bactericidal activity and electrical conductivity when tested for antibacterial activity and dielectric behavior, respectively, which were discussed in detail.