Synthesis and characterization of Fe 3 O 4 nanoparticles and its nanocomposite decorated with CQDs: fluorescence and stable magnetite

Abstract Highly stable and magnetized Fe3O4 nanoparticles (NPs) were synthesized using a simple and rapid one-step co-precipitation technique through a chemical reaction between Fe3+ and Fe2+ ions. Subsequentially, glycerin (GC) and citric acid (CA) as an organic precursor of carbon quantum dots (CQDs) source were added and two types of nanocomposites including Fe3O4@GC and Fe3O4@GC@CA were fabricated hydrothermally. The acquired nanocomposites were characterized by Fourier transform infrared (FT-IR) spectrometry, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, dynamic light scattering (DLS), vibrating sample magnetometry (VSM), photoluminescence (PL) spectroscopy, thermogravimetric analysis (TGA), and Brunauer–Emmett–Teller (BET) analysis. SEM micrographs revealed that Fe3O4@GC and Fe3O4@GC@CA nanocomposites have an average diameter size of 40 nm and 49.5 nm, respectively. In addition, their crystallite size was calculated using the Debye-Scherrer equation that was obtained 10.3 and 11.7 nm for Fe3O4@GC and Fe3O4@GC@CA nanocomposites, sequentially. These results indicated the proper coating of Fe3O4@GC nanocomposite with citric acid. Comparing the TGA profiles of the samples showed that a higher percentage of weight loss was reported for the Fe3O4@GC@CA nanocomposite, which was due to the addition of an excess amount of citric acid during the synthesis process. Meanwhile, the outcomes demonstrated that synthesized nanocomposites have good photoluminescence with different peaks as well as high magnetic properties that make them useful for different application fields. Furthermore, zeta potential and color stability pictures showed high stability for acquired magnetic nanocomposites.