Quaternary ammonium salts intercalated α-ZrP compounds for adsorption of phenolic compounds

By using methylamine as the colloidization agent to weaken the interactions of α-ZrP laminate, the quaternary ammonium salts of DTAB, TTAB, CTAB and STAB were successfully intercalated into the methylamine pre-pillared α-ZrP, denoted as DTAB-ZrP, TTAB-ZrP, CTAB-ZrP and STAB-ZrP, respectively. XRD, FTIR, TEM and N2 sorption were used to characterize the intercalated compounds, and the arrangements of intercalated quaternary ammonium salts within ZrP were supposed according to the results. It was shown that the interlayer distances were increased from 0.76 nm to 2.10-3.50 nm and the intercalated quaternary amine salt cationic bonded with PO− anion through electrostatic interaction. The phenolic compounds adsorption results have demonstrated that all the four intercalated compounds have good adsorption performance, and CTAB-ZrP show the highest maximum adsorption amounts of 0.90, 1.25 and 1.34 mmol g−1, for phenol, 2-chlorophenol and 2,4-dichlorophenolare, respectively. The adsorption isotherms of phenolic compounds are linear with the C0 of 2.0-6.0 mmol L−1 and fit well to both the Linear and the Freundlich models, which indicated that the adsorption mechanism is mainly partition effects of organic phase within ZrP interlayer.

Highlights► Different quaternary ammonium salts intercalated α-ZrP were synthesized. ► The intercalation mechanism is proposed according to the experimental results. ► The intercalation compounds show high performance of phenolic compounds adsorption. ► Adsorption mechanism of intercalated compounds for phenols is also proposed.