In situ green synthesis of Ag nanoparticles on herbal tea extract (Stachys lavandulifolia)-modified magnetic iron oxide nanoparticles as antibacterial agent and their 4-nitrophenol catalytic reduction activity.

For first time, we designed an environment friendly technique novel hybrid magnetic nanocomposite with the potency of both reducing and stabilizing agent for immobilization of metal nanoparticles. Stachys lavandulifolia extract having a lot of carbonyl and phenolic hydroxyl functional groups can be applied in the Fe3O4 NPs modification. Furthermore, in aqueous solution, the complexation feasibility of polyphenols with silver ions can enhance the capacity and surface properties of the Fe3O4@S. lavandulifolia NPs for sorbent and in situ reduction of silver ions. So, as both the stabilizing and reducing agent, the novel magnetic nano-sorbent (Fe3O4@S. lavandulifolia NPs) has potential ability for silver nano particles immobilization to create a novel magnetic silver nanocatalyst. So that, no additional reductants, toxic reagents and intricate instruments are needed to prepare the catalyst. The morphology, structure, and physicochemical properties were elucidated by several analytical methods like, field emission scanning electron microscope (FESEM), high resolution transmission electron microscopy (HRTEM) images, energy-dispersive X-ray spectroscopy (EDS), vibrating sample magnetometer (VSM), X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy, and inductively coupled plasma (ICP). As recyclable nanocatalyst, Fe3O4@S. lavandulifolia/Ag indicated high catalytic activity for 4-nitrophenol (4-NP) reduction at ambient temperature. Ultimately, the Fe3O4@S. lavandulifolia/Ag antibacterial properties was examined against two bacteria (Staphylococcus aureus (Staph. aureus) and Escherichia coli (E. coli)) and indicated its antibacterial activities against gram negative (E. coli) bacteria and gram positive (Staph. aureus).