Facile fabrication of silver on magnetic nanocomposite (Fe3O4@Chitosan -AgNP nanocomposite) for catalytic reduction of anthropogenic pollutant and agricultural pathogens.

In this work, a novel approach was developed to synthesis advance magnetic nano-catalyst; Fe3O4@Chitosan -AgNP nanocomposite. It is made up of chitosan (fish industry-waste) doped onto the magnetic core with active silver nanoparticles on the exterior shell using NaBH4 as reductant and total soluble solids (dairy effluent-waste) as a stabilizing agent. TEM images confirm the average mean diameter of composed nanocatalyst about 8 ± 2.2 nm. SEM images, EDX spectra, and ICP-MS data confirmed the co-presence of Ag, Fe, C, and O elements with a calculated percentage weight of Ag as 8.15%. XRD patterns revealed the product was chitosan doped iron oxide with surfaced silver nanoparticles. XPS and FTIR confirm composition, elemental electronic state, and binding energy. Additionally, it is utilized as an effective solid-phase catalyst for the reduction of anthropogenic pollutant p-nitrophenol to p-aminophenol. It has a very convenient magnetic separability. ICP-Ms data for cumulative silver release shows prepared nanocatalyst remains active and stable even after recycled for more than 15 times. Also, an excellent antifungal activity was observed against the agricultural pathogens such as Colletotrichum coccodes, Aspergillus niger, and Pyricularia sp. Thus, functionalized nanostructures Fe3O4@Chitosan -AgNP magnetic nanocomposite can probably hold greater potential in catalysis and agriculture applications.