Ammonia-modified graphene sheets decorated with magnetic Fe3O4 nanoparticles for the photocatalytic and photo-Fenton degradation of phenolic compounds under sunlight irradiation

Abstract

Synthesis of easily separable and eco-friendly efficient catalyst with both photocatalytic and photo-Fenton degradation properties is of great importance for environment remediation application. Herein, ammonia-modified graphene (AG) sheets decorated with Fe₃O₄ nanoparticles (AG/Fe₃O₄) as a magnetically recoverable photocatalyst by a simple in situ solution chemistry approach. First, we have functionalized graphene oxide (GO) sheets by amide functional group and then Fe₃O₄ nanoparticles (NPs) are doped onto the functionalized GO surface. The AG/Fe₃O₄ nanocomposite showed efficient photocatalytic activity towards degradation of phenol (92.43%), 2-nitrophenol (2-NP) (98%) and 2-chlorophenol (2-CP) (97.15%) within 70-120min. Consequently, in case of photo-Fenton degradation phenomenon, 93.56% phenol, 98.76% 2-NP and 98.06% of 2-CP degradation were achieved within 50-80min using AG/Fe₃O₄ nanocomposite under sunlight irradiation. The synergistic effect between amide functionalized graphene and Fe₃O₄ nanoparticles (NPs) enhances the photocatalytic activity by preventing the recombination rate of electron-hole-pair in Fe₃O₄ NPs. Furthermore, the remarkable reusability of the AG/Fe₃O₄ nanocomposite was observed up to ten cycles during the photocatalytic degradation of these phenolic compounds.

Keywords: 2-chlorophenol; 2-nitrophenol; Fe(3)O(4) nanoparticle; Graphene; Phenol; Photo-Fenton degradation; Photodegradation.