Sintesis dan Karakterisasi Nanokomposit Fe3O4/N-Doped Carbon Dots Berbasis Cangkang Biji Karet (Hevea brasiliensis) dengan Metode Sonikasi

Abstract

Research on biomass-based nanomaterials has the potential to produce environmentally friendly materials with outstanding functional properties. Nitrogen-doped Carbon Dots (N-CDs) are nanomaterials known for their strong fluorescence, relatively high band-gap energy, and excellent water solubility. Fe₃O₄, on the other hand, is recognized for its strong and stable magnetic properties. This study aims to synthesize and characterize Fe₃O₄/N-CDs nanocomposites using the sonication method. N-CDs were synthesized from rubber seed shells (Hevea brasiliensis) with urea as the Nitrogen source through a hydrothermal method at 180 °C for 16 hours. The nanocomposites were then prepared using sonication. N-CDs were successfully synthesized, confirmed by the appearance of blue fluorescence under UV light and TEM analysis showing spherical morphology with an average particle size of 2.8 nm. FTIR analysis identified the presence of –OH, N–H, C–C, C=O, C=C, C–N, and C–O functional groups in N-CDs, along with Fe–O vibrations in the Fe₃O₄/N-CDs nanocomposite. The PL spectra exhibited emission peaks at 425 nm for N-CDs and 445 nm for Fe₃O₄/N-CDs. UV-Vis analysis showed absorption peaks at 234 nm and 310 nm for N-CDs, and 318 nm and 372 nm for the nanocomposite, with corresponding band-gap energies of 3.07 eV and 2.78 eV. The Fe₃O₄/N-CDs nanocomposite displayed superparamagnetic behavior, indicated by an Mr/Ms ratio < 0.1 and an Ms value of 56.56 emu/g obtained from Vibrating Sample Magnetometer (VSM) analysis. Surface Area Analyzer (SAA) measurements revealed a specific surface area of 19.46 m²/g, an average pore diameter of 16.12 nm, and a total pore volume of 0.16 cm³/g. Scanning Electron Microscope (SEM) analysis showed irregular morphology with N-CDs distributed on the surface of Fe₃O₄. EDX results identified Fe, O, C, and N elements, confirming the successful formation of the Fe₃O₄/N-CDs nanocomposite. Overall, the findings demonstrate that Fe₃O₄/N-CDs nanocomposites were successfully synthesized.