Adsorption behavior and mechanism of acidic blue 25 dye onto cucurbit[8]uril: A spectral and DFT study

作者：Luo, Hanhan; Huang, Xiangyu; Luo, Yuhan; Li, Zhuang; Li, Lan; Gao, Chao^*; Xiong, Jinyan^*; Li, Wei^*

来源：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 2018, 193: 125-132.

DOI：10.1016/j.saa.2017.12.006

• CB [8]
• Acidic blue 25
• Adsorption

The acidic blue 25 (AB25) dye was efficiently adsorbed by CB [8]; the saturated adsorption capacity (q(exp)) reached 434.8 mg/g and was far higher than those of previous reported adsorbents. The Langmuir and Freundich isotherms were used to fit the equilibrium data, and the results showed that the Freundlich isotherm seemed to agree better with the AB25 adsorption. The adsorption kinetics followed the pseudo-second-order model. Calculated thermodynamic parameters showed that the adsorption of AB25 onto CB [8] was a spontaneous and enthalpy-driven process. The adsorption mechanism was explored by N-2 adsorption-desorption, TG, FT-IR, UV-vis as well as MD simulation and DFT calculations. TG analysis revealed that a new inclusion complex was produced, and FT-IR,UV-vis spectrum and DFT calculations verify its structure. In this inclusion complex, the AB25 dye molecule inserted into cavities of CB [8] from portal, and the sulfonate and phenyl groups stayed in the hydrophobic cavity. TDDFF calculations indicated that all excitation arisen from pi -> pi* transition.

• 出版日期2018-3-15
• 单位武汉纺织大学