Enhancement in photoluminescence performance of carbon-based Fe3O4@ZnO–C nanocomposites

This research synthesized a Fe3O4@ZnO–C nanocomposite with a core-shell structure using the coprecipitation method. XRD diffractograms indicate the formation of Fe3O4 and ZnO phases, where Fe3O4 has a cubic crystal system while ZnO has a hexagonal crystal system. The presence of carbon (graphite and carbon quantum dots) in Fe3O4@ZnO–C does not change the crystal structure of Fe3O4@ZnO. TEM images show the formation of a core-shell structure in the Fe3O4@ZnO nanocomposite. FTIR measurements show the stretching vibration of the C–O and CC bonds on the Fe3O4@ZnO–C and Fe3O4@ZnO-CQD samples comes from carbon, meaning that the nanocomposites have been coupled with carbon. The optical properties of the nanocomposites were characterized using Photoluminescence (PL) spectroscopy. The addition of carbon and CQD increases photoluminescence significantly. The Fe3O4@ZnO–C photoluminescence intensity is in the orange emission wavelength range, while Fe3O4@ZnO-CQD is in the green emission wavelength range.