Annealing effect on physical properties and antibacterial performance in green-Turmeric co-precipitated silver-cobalt-ferrite nanoparticles utilizing fine-sediments as iron-cations source-materials

• AgCFO-NPs synthesized via green coprecipitation & utilize fine sediment. • The antibacterial mechanism is supported by Ag + release ROS, & membrane disruption. • Highest zone-inhibition of 16.70 mm (at 300 °C) in S. aureus and 14.88 mm (at 200 °C) in E. coli . The silver-substituted cobalt ferrite nanoparticles (AgCFO-NPs) have been successfully synthesized using green-coprecipitated method with turmeric ( Curcuma Longa Linn ) extract with utilizing a fine-sediment iron-sand as Fe 3+ ions source. XRD results show the spectral data is in accordance with ICDD No. 22–1086, thus confirming that the cobalt ferrite nanocrystal phase is present. Crystallite size calculation increase D = 22.00 nm to 31.45 nm with an increasing annealing temperature ( T a = 100 °C to 500 °C). Characteristic FTIR curve show adsorption-peak band around v 1 = ∼569.99 cm −1 and v 2 = ∼399.28 cm −1 indicate to the intrinsic vibration of metal–oxygen bonds at the tetrahedral and octahedral sites of the spinel structure. Furthermore, temperature of annealing T a tunes the magnetic properties of the AgCFO-NPs . SEM result show that the green synthesis realizes nanoparticles wrapped into large granules ( T a = 100 °C and 200 °C) and then the granular wrapping gradually disappears with the increase of the T a (300 °C, 400 °C and 500 °C). Finally, antibacterial performance (for Staphylococcus aureus and Escherichia coli ) show that the highest zone-inhibition of 16.70 mm (at 300 °C) in S. aureus and 14.88 mm (at 200 °C) in E. coli are observed, respectively. Here, nanoparticles utilizing fine-sediment iron-sand are promising as an effective and biocompatible antibacterial agent in next-future medical application.