MIL-101(Cr)/graphene hybrid aerogel used as a highly effective adsorbent for wastewater purification

Abstract

MIL-101(Cr)/graphene aerogel (MIL-101(Cr)/GA) was synthesized using a two-step synthesis and used as a high efficient adsorbent for wastewater purification. The as-prepared MIL-101(Cr)/GA was characterized using XRD, FTIR and Raman spectroscopy, XPS and FESEM to investigate its structure, composition and morphology. MIL-101(Cr)/GA exhibited a 3D interconnected macroporous framework comprised of graphene sheets, on which MIL-101(Cr) particles were dispersed uniformly. Dyes, organic solvents and oils were used to evaluate the adsorption performance of MIL-101(Cr)/GA, which exhibited an excellent adsorption capacity for both anionic methyl orange (331.5 mg g−1) and cationic rhodamine B (345.7 mg g−1) as well as 51–101 times its own weight of various solvents/oils. In addition, the MIL-101(Cr)/GA showed superior recycling stability for dyes and a rapid adsorption rate for solvents/oils. The excellent adsorption performance was attributed to a synergistic effect between MIL-101 and the graphene aerogel. The kinetic behavior for adsorption observed for MIL-101(Cr)/GA was well-fitted by a pseudo-second-order kinetic model. It is envisaged that MIL-101(Cr)/GA will be a promising adsorbent for the removal of pollutants and wastewater purification.