Adsorption of chromium by functionalized metal organic frameworks from aqueous solution

ABSTRACT

Based on Cu-BTC metal-organic framework, thiol-functionalized and amino functionalized materials were prepared by the modified Stöber method. Then, the Cu₃(BTC)₂ and the functionalized materials were characterized by means of X-ray diffraction, SEM-EDS and FT-IR analysis. The adsorption properties of two materials for Cr(VI) were investigated. Both functionalized materials show good adsorption under acidic conditions. Through adsorption model analysis, the adsorption of Cr(VI) by the two materials were more in line with the pseudo-second-order kinetic equation. The adsorption capacities of Langmuir isothermal fitting were 15.17 mg g⁻¹ and 7.17 mg g⁻¹, respectively. During the adsorption process, the functionalized material does not swell and is insoluble in water. After five adsorption-desorption cycles, the adsorption capacity is basically constant and the material can be reused. The results show that the above two functionalized MOFs have good application prospects in the adsorption and removal of heavy metal Cr(VI) in aqueous solution.

GRAPHICAL ABSTRACT

KEYWORDS:

• Metal organic frameworks
• chromium
• functionalized
• adsorption
• kinetic model

Acknowledgements

Thanks to the experimental team for their help. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Xinfeng Xiao http://orcid.org/0000-0001-6646-6995