Facile synthesis of graphite oxide/MIL-101(Cr) hybrid composites for enhanced adsorption performance towards industrial toxic dyes

Graphite oxide (GrO), as a superb platform with highly dense arrays of atoms and abundant functionalities, can increase dispersive forces within metal-organic frameworks (MOFs), which provides a feasible strategy to control physicochemical properties of MOFs. In this study, a series of hybrid GrO/ MIL-101(Cr) (GrO@MCr) nanocomposites were readily prepared via hydrothermal synthesis. The prepared composites were applied to remove methyl orange (MO) and reactive blue 198 (RB198) as organic pollutants from an aqueous solution. The surface area of GrO@MCr composite increased from 2980 to 3540 m(2) g(-1) with increasing GrO loading amount from 0 to 6.0 wt.%. The highest adsorption capacities of MO (235 mg g-1) and RB198 (175 mg g(-1)) were obtained at 25 degrees C and pH = 5.5 using 6 wt.% GrO loaded GrO@MCr composite; these values were 2.3 and 1.97 times higher than that of pristine MIL101(Cr). The reusability and stability analyses showed that the sorption capacities of MO and RB198 onto the fabricated GrO@MCr decreased to 89% and 86%, respectively, after five adsorption-desorption cycles. Moreover, the adsorption kinetics and adsorption isotherms were studied in detail to investigate the adsorption mechanism. (c) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Automated summary

In this study, a series of hybrid GrO/MIL-101(Cr) (GrO@MCr) nanocomposites were prepared via hydrothermal synthesis, showing increased adsorption capacities for organic pollutants MO and RB198. The adsorption mechanism was detailedly studied in this research.