β-Cyclodextrin/diatomite composite for efficient remove dyes via host-guest encapsulation and the insight of mechanism

A facile, green and effective method was developed to synthesis porous β -cyclodextrin/diatomite ( β -CD/DA) composite, the β -CD was crosslinked onto the surface of DA via a mild reaction conditions. The β -CD/DA shown good thermal stability and adsorption capability, that was successfully used for remove organic dyes from water system with efficiency nearly achieve to 100 %. Furthermore, the mechanism of the adsorption of organic dyes by macrocyclic molecules was investigated through the NMR spectra. The downfield NMR shift of the proton resonances of included R6G were observed from inclusion complex of R6G/ β -CD. The downfield shift of the NMR peak of the R6G was due to the hydrogen bonding interaction formed during the adsorption process. These result would be very meaningful for studying the mechanism of the adsorption of organic dyes by macrocyclic molecules.