One-pot synthesis of multifunctional magnetic N-doped graphene composite for SERS detection, adsorption separation and photocatalytic degradation of Rhodamine 6G

Abstract This work reports a one-pot solvothermal synthesis approach of magnetic γ-Fe 2 O 3 /N-rGO composite and its multifunctional application for detection, adsorption removal and degradation of organic pollutants. The uniform dispersed γ-Fe 2 O 3 nanoparticles (NPs) are in situ grown on the surface of nitrogen doped reduced graphene oxide (N-rGO) sheets, thus forming a three-dimensional (3D) γ-Fe 2 O 3 /N-rGO composite with high specific surface area (146.2 m 2 ·g −1 ). The morphology and textural properties of the samples were characterized by scanning and transmission electron microscopies, X-ray diffraction, Raman and X-ray photoelectron spectroscopies. The γ-Fe 2 O 3 /N-rGO composite with 3D interconnected porous structure possesses multifunctional performance for dye removal with convenient magnetic separation operation. It exhibits good removal ability for Rhodamine 6G (R6G) with an adsorption capacity of 44.0 mg·g −1 . Meanwhile, the γ-Fe 2 O 3 /N-rGO composite shows a high sensitive surface-enhanced Raman spectroscopy (SERS) response toward R6G molecules where the detection limit is as low as to 5 × 10 −7  mol·L −1 . Besides, it also serves as a photocatalyst to degrade the adsorbed R6G molecules under in situ SERS monitoring. Thus, the multifunctional γ-Fe 2 O 3 /N-rGO composite can present a promising potential for organic dye wastewater treatment and other applications.