Enhanced Antibacterial Activity and Photo-Catalytic Properties of ZnO Nanoparticles: Pedalium Murex Plant Extract-Assisted Synthesis.

Semiconductor ZnO samples with two different morphologies such as nanoparticles (ZnO-NPs) and nano-sheets (ZnO-NSs) was successfully prepared by microwave heating (MHM) and modified sol-gel (SGM) method, respectively using Pedalium Murex plant extract as the bio-reducing agent. Structural, purity and morphology of the samples was examined by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. Optical property analysis and band gap calculation were carried out by UV-Visible diffuse reflectance (DRS) and photoluminescence (PL) spectroscopy techniques. Kubelka-Munk method was used to measure band band gap of the samples and it shows 3.42 eV and 3.23 eV for ZnO-NPs and ZnO-NSs, respectively. The antibacterial activities of ZnO-NPs and ZnO-NSs against both gram positive ( Bacillus subtilis , Staphylococcus aureus ) as well as gram negative bacteria ( Proteus mirabilis , Salmonella typhi ) were tested by modified disc diffusion method and showed important antibacterial activity against P. mirabilis and S. typhi. The photocatalytic activity of ZnO nano-catalysts (ZnO-NPs and ZnO-NSs) for the degradation of methylene blue (MB) dye was studied under solar lighting and the results showed that the samples ZnO-NPs with smaller particle size considerable degradation of MB than ZnO-NSs.