An enhanced adsorption of organic dyes onto NH 2 functionalization titanium-based metal-organic frameworks and the mechanism investigation
| Autor: | Yu-Han Fan, Shou-Wen Zhang, Xiao-Shui Li, Shihua Qi, Shi-Bin Qin |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Aqueous solution
Hydrogen bond fungi Enthalpy chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Adsorption chemistry Chemical engineering Mechanics of Materials General Materials Science Freundlich equation Metal-organic framework 0210 nano-technology Vat dye Titanium |
| Zdroj: | Microporous and Mesoporous Materials. 263:120-127 |
| ISSN: | 1387-1811 |
| DOI: | 10.1016/j.micromeso.2017.12.016 |
| Popis: | In this paper, the enhanced adsorption properties and mechanism of NH2 functionalization titanium-based metal-organic frameworks (NH2-MIL-125(Ti)) towards various organic dyes was investigated. First, MIL-125(Ti) and NH2-MIL-125(Ti) were successfully synthesized and characterized. The as-prepared Ti-MOFs can be facilely magnetized by adsorbing Fe3O4 nanoparticles on their surfaces via a Lewis acid-base interaction. Then, three types of dye (cationic dye, anionic dye and vat dye) adsorption measurements show that the electrostatic interaction, π-π stacking interaction and pore filling all play important roles in the adsorption process of both Ti-MOFs in aqueous solutions. Particularly, the amino group in NH2-MIL-125(Ti) can provide extra hydrogen bonding interaction towards target substances, which results in a stronger interaction force and a higher adsorption capacity than that of MIL-125(Ti). The adsorption kinetics and isotherm suggested the adsorption process of both Ti-MOFs towards methylene blue (MB) were better fitted to a pseudo-second-order kinetic and Freundlich isotherm model. The adsorption thermodynamic experiments demonstrated that adsorption of MB on both Ti-MOFs was spontaneous. However, their values of enthalpy and entropy were opposite, indicating that their adsorption processes were controlled by enthalpy and entropy effect, respectively. |
| Databáze: | OpenAIRE |
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