Sonochemical synthesis of silica supported iron nanoparticles for enhanced removal of Cr(VI) species from aqueous medium

Various biogenic routes were explored for the synthesis and biocompatible use of iron nanoparticles. Nanoparticle synthesis using plant extracts gaining lots of research attention in recent decade due to the ease of availability, non-toxic nature and its efficient ability to act as reducing as well as capping agents. The present study focused on green environmentally feasible synthesis of iron nanoparticles using guava (Psidium guajava) leaf extract which serve as reducing as well as capping agent. For additional stabilization, the prepared nanoparticles were supported on silica gel. The sonochemically synthesized iron nanocomposite system for Cr(VI) removal has been explored first time for Cr(VI) adsorption. The derived nanoparticles were qualitatively analyzed using various instruments such as FTIR, XRD, SEM, and SEM–EDX. The synthesized material was used for the removal of Cr(VI) from the aqueous solution. Maximum removal of 100% was obtained at an optimized parameters (solution pH = 6.2; adsorbent dose = 4 g/L; contact time = 60 min; initial Cr(VI) conc. = 10 mg/L). The adsorption data agrees well with the Langmuir isotherm model, and kinetic investigation demonstrates that the Cr(VI) adsorption data are in consistent with the pseudo-second-order kinetic model.