Microwave-assisted synthesis of UIO-66 and its adsorption performance towards dyes

Abstract

In this paper, a microwave-assisted method in the presence of an additive has been employed to quickly and prepare UIO-66 (MWHAc-UIO-66) in high yield. The microwave/additive method gives rise to a full octahedral morphology of ~250 nm particles and a highest surface area 1533.53 m² g⁻¹, which is confirmed by the surface area of MWBA-UIO-66 (1661.01 m² g⁻¹), prepared with benzoic acid as the additive. The adsorption results for a low-concentration of acid chrome blue K show that MW-UIO-66 and MWHAc-UIO-66 have excellent adsorption abilities (~98%), while HHAc-UIO-66 is also satisfactory (~85%), which are far better than activated carbon. Moreover, the saturated adsorption amount of acid chrome blue K for MWHAc-UIO-66 can be up to ~15%. The adsorption of different dyes shows that MWHAc-UIO-66 is attractive to charged dyes. Reusability experiments indicate that sulfuric acid can facilitate dye desorption from MWHAc-UIO-66 instead of a base or salt.