Photocatalytic and antibacterial properties of Ag/ZnO/NC nanocomposite

Recently, organic and inorganic pollutants including heavy metals, effluents, dyes, and bacteria have been removed from wastewater and other environmental settings using nanomaterials. Combining two or more nanomaterials to form nanocomposites offers improved and tailored properties for these applications. Metal-polymer nanocomposite exhibit elevated optical, electrical, thermal and mechanical properties, which make them interesting candidates for the manufacturing of functional devices as well as other industrial applications. In this study, Ag/ZnO/cellulose nanocomposite was synthesised through in-situ solution casting method which offers a good adhesion and dispersity of nanostructured materials. The morphological properties of the synthesized nanostructures were studied from scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) measurements. X-ray diffractometer (XRD) patterns were recorded to reveal the structural properties of the samples. The optical absorbance was measured using a UV-Vis-NIR spectrophotometer and used to determine the energy band gap (Eg). From SEM analysis, nanodiscs-like structures were observed for ZnO while nanospheres and nanosheets were observed for Ag and cellulose, respectively. EDS confirmed the presence of only Zn, O, Ag and C. XRD analysis pointed to cellulose

monoclinic type-1. Peaks corresponding to typical hexagonal wurtzite structure for ZnO and also to face-centred-cubic Ag structure were identified. Photodecomposition of aqueous methylene blue (MB) under direct sunlight irradiation was monitored to study the photocatalytic activity of the nanocomposite. About 92% of MB was degraded in the presence of Ag/ZnO/cellulose nanocomposite. The antibacterial activity of the prepared

samples was investigated against three pathogenic bacteria species; Gram negative Escherichia coli, Gram positive Staphylococcus aureus and Gram positive, spore forming Bacillus subtilis. The prepared anocomposite exhibited strong activity against the growth of all the bacterial species though in different quantified measures.