Adsorptive removal of tetracycline and methylene blue from aqueous solution with a water resistance copper-based metal–organic framework

Abstract

Copper-1,3,5-benzenetricarboxylic acid (Cu–BTC) is a research hotspot for metal–organic frameworks (MOFs) because of its remarkable intrinsic structural features. However, the water instability issue has restricted its practical applications, such as capturing organic contaminants from wastewater. Herein, a novel Cu–BTC(OMe) was achieved through a convenient hydrothermal synthesis method with the partial group substitution of carboxyl with methoxy (OMe). The Cu–BTC(OMe) possesses good water resistance and exhibits excellent capturing performances toward methylene blue (MB) and tetracycline (TC). The adsorption process can be perfectly described by the Langmuir model and the pseudo-second-order kinetic equation. Importantly, Cu–BTC(OMe) is sustainable and stable, maintaining more than 90% of the initial MB and TC uptakes after recycling five times. In brief, grafting the OMe in the structure of Cu–BTC(OMe) could effectively boost its water stability and is favorable for synchronous MB and TC capture abilities.