Clicking graphene oxide and Fe3O4 nanoparticles together: an efficient adsorbent to remove dyes from aqueous solutions

Nanohybrid of graphene oxide (GO) and azide-modified Fe 3 O 4 nanoparticles (NPs) were fabricated using click reaction. First, Fe 3 O 4 NPs were modified by 3-azidopropionic acid. Then, click-coupling of azide-modified Fe 3 O 4 NPs with alkyne-functionalized GO was carried out in the presence of CuSO 4 ·5H 2 O and sodium l -ascorbate at room temperature. The attachment of Fe 3 O 4 NPs onto the graphene nanosheets was confirmed by Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy, thermogravimetric analysis, energy dispersive X-ray spectrometry and X-ray diffraction spectrometry. As the FTIR spectroscopy and energy dispersive X-ray spectrometry analysis showed, the final magnetic graphene nanosheets were also reduced by sodium ascorbate which is a merit for click-coupling reactions. The specific saturation magnetization of the Fe 3 O 4 -clicked GO was 44.3 emu g −1 . The synthesized hybrid was used in the adsorption of methylene blue and congo red (CR). The adsorption capacities in the studied concentration range were 109.5 and 98.8 mg g −1 for methylene blue and CR, respectively.