Magnetically Separable Nanospherical g-C3N4@Fe3O4 as a Recyclable Material for Chromium Adsorption and Visible-Light-Driven Catalytic Reduction of Aromatic Nitro Compounds

摘要

Graphite-like graphitic carbon nitride (g-C3N4) has gained considerable interest in the past few years. However, merely a few studies have been undertaken regarding the application of g-C3N4 for metal adsorption and visible-light driven reduction of aromatic nitro compounds. Here, we describe a versatile method for the preparation of g-C3N4 nanocomposite decorated with magnetite nanoparticles (g-C3N4@Fe(3)O(4)NPs) that subsequently showed their efficiency in sequestration of Cr(VI)/Cr(III) and NaBH4-mediated conversion of 2-nitroaniline (2-NA) and 4-nitroaniline (4-NA) under visible-light exposure. The as-synthesized g-C3N4@Fe(3)O(4)NPs adsorbent revealed excellent water dispersibility, superior magnetic property, and porous structure. Numerous surface hydroxyls ( OH) and amino groups (-N, -NH, -NH2) enabled g-C3N4@Fe(3)O(4)NPs to rapidly isolate Cr(VI) from aqueous solution through applying an outer magnetic field. The adsorbed Cr(VI) on the g-C3N4@Fe(3)O(4)NPs surface offered a maximum equilibrium adsorption capacity of 555 mg g(-1) and their absorption behavior followed the Langmuir isotherm and pseudo-second-order kinetics model. The morphology, surface properties, crystalline structure, and chemical compositions of g-C3N4@Fe(3)O(4)NPss were thoroughly investigated. In real-world applications, g-C3N4@Fe(3)O(4)NPs was implemented for the determination of total chromium in industrial soil sludge samples. Additionally, NaBHerinduced reduction of 2-NA to 2-aminoaniline and 4-NA to 4-aminoaniline catalyzed by g-C3N4@Fe(3)O(4)NPs (catalyst loading as low as 20 mg) was achieved within 8 min.