Photodegradation Of Nanometer Carbon Materials In Wastewater

Graphene,fullerene(C60),multi-walled carbon nanotubes(MWCNTs)and their derivatives have been discharged into water due to their popular application in functional materials.Many investigations show that they would harm organisms.Therefore,development of an efficient method for removing graphene,C60,MWCNTs and their derivatives from water is important.Under UV-light irradiation,graphene,C60 and MWCNTs in water can be oxidized to give graphene oxide(GO),oxidized C60(O-C60)and oxidized MWCNTs(O-MWCNTs),therefore,degradation of GO,O-C60 and O-MWCNTs is a vital step for removal of graphene,C60,MWCNTs and their derivatives from water.In this paper,GO,O-MWCNTs and O-C60 in water were effectively degraded by photo-Fenton,photo-Fenton-like and environment-friendly method to give CO2,H2O and a few of organic acids.The degradation process and intermediates were determined by total organic carbon,ultraviolet-visible absorption,liquid chromatography-tandem mass spectrometry,X-ray diffraction,nuclear magnetic resonance,fourier transform infrared spectroscopy,transmission electron microscopy,scanning electron microscopy and elemental analysis.Quantum chemistry calculation using DFT method in Gaussian09 software was used to study nanometer carbon materials and degradation intermediates.Based on these experimental data of degradation intermediates and Gaussian calculations,the degradation mechanisms of GO,O-MWCNTs and O-C60 in water were supposed.