Nanostructure, Band Gap, and Antibacterial Activity of Spinel Fe₂MO₄/OO Magnetic Fluids

Abstract

This research aimed at investigating Fe2MO4 ferrofluids nanostructure, with M was Fe, Ti and Cr. Fe2MO4 nanoparticles were synthesized through coprecipitation method, and the phase and crystallinity were analyzed using XRD instrument. The obtained results showed the Fe3O4 phase, but there was a shift in diffraction peak position contributed by the doping of Ti2+ and Cr3+ ions. Furthermore, a similar change occurred in the lattice parameter, crystal volume, and particle size. The particle sizes of Fe3O4, Fe2TiO4, and Fe2CrO4 particles were 10.2, 13.4, and 6.9 nm, respectively. The functional groups of the Fe2MO4/OO ferrofluids were characterized using FTIR and obtained the Fe-O stretching band shift due to the modification of structure. Furthermore, FTIR analysis was used as a reference to confirm functional groups of the ferrofluids. The absorbance data collection was performed through the characterization using UV-Vis instrument, and there was intervalence charge transfer at a wavelength near infra-red indicating there was Fe element and nanoparticle interface which raised an optimum absorption at the interval of 400-550 nm. Furthermore, through the obtained absorbance data, there was an energy gap of 2.2-2.24 eV. Interestingly, the results of antibacterial testing results through the dilution method showed a modification of structure could increase the antibacterial activity of the Fe2MO4/OO ferrofluids by minimizing the percentage of surviving colony number.

The Beneficial Role of Nano-Sized Fe3o4 Entrapped in Ultra-Stable Y Zeolite for the Complete Mineralization of Phenol by Heterogeneous Photo-Fenton Under Solar Light

“…In detail, the scavenger probe molecules used in the activity tests were: isopropanol (IPA, 10 mmol L − 1 ) for hydroxyl radicals (Sacco et al, 2021), and silver nitrate (SN, 10 mmol L − 1 ) for electrons (Schneider et al, 2020;Saragi et al, 2018). Indeed, it must be remarked that magnetite possesses an interesting band gap energy (1.8-2.2 eV) making it suitable to be excited by solar light (Abadiah et al, 2019), so the contribution of photocatalysis in the reaction system has been evaluated (Fig. SI14).…”

“…Recently, magnetite (Fe 3 O 4 ) and magnetite based-catalysts received great attention both as a heterogeneous Fenton and photo-Fenton catalyst because of their low cost, the possibility of magnetic separation, nontoxicity, and good stability (Liu et al, 2021;Huang et al, 2022). Fe 3 O 4 possesses an inverse spinel structure, (Fe 3+ ) A (Fe 2+ Fe 3+ ) B O 4 where A and B represent tetrahedral and octahedral atom positions, respectively (Abadiah et al, 2019). Phenol can be removed by magnetite micrometric and nanometric particles where the high specific surface area possesses a relevant role in sorption and/or redox processes.…”