Elaboration of Fe3O4/ZnO-C hybrid nanocomposites with highly photoluminescence intensity

Abstract

This study underscores the role of nanocarbons in enhancing the photoluminescence (PL) of Fe₃O₄/ZnO nanocomposites and their potential applications in biomedicine. As previously known, the PL intensity of ZnO decreased due to the quenching effect by Fe₃O₄. This study investigated the effect of carbon addition on the crystal structure, photoluminescence, and magnetic properties of the nanocomposites. Four nanocarbon mass variations, i.e., 0.2, 0.1, 0.05, and 0.03 g, were used to synthesize the Fe₃O₄/ZnO-C nanocomposites. The X-ray diffraction (XRD) measurements of the nanocomposites displayed Fe₃O₄, ZnO, and carbon phase structures with no impurities. The transmission electron microscopy (TEM) images and fast Fourier transform (FFT) analysis confirm that the ZnO crystals and carbon covered the Fe3O4 nanoparticles. The Fourier transform infrared spectroscopy (FTIR) analysis reported a C-O absorption peak, corresponding to the hybridization between carbon and the Fe₃O₄/ZnO nanocomposites. The VSM data indicated that higher carbon concentration led to lower magnetic saturation. Likewise, PL measurements reported that adding a small amount (0.05 g) of carbon could significantly increase PL intensity. The strongest light emission was found with 0.05 g of carbon, showing the brightest orange light at a wavelength of 660 nm; the magnetic saturation measured 22.05 emu/g, and the crystallite size obtained was 21.36 nm for Fe₃O₄ nanoparticles and 21.34 nm for ZnO nanoparticles. The composition of 0.05 g carbon is the optimum value for producing photoluminescence and magnetic properties for biomedical applications. Therefore, the optical and magnetic properties of the Fe₃O₄/ZnO nanocomposite could be adjusted by surface modification with carbon to improve their application in imaging, diagnostics, and cancer treatment.