Aqueous-phase synthesis of heterojunction molecular imprinted photocatalytic nanoreactor via stable interaction forces for improved selectivity and photocatalytic property

Abstract

Common molecular imprinted photocatalysts are usually prepared in highly toxic organic solvent medium, which will be disturbed by water molecules and swelling differences when used for selective recognition in the aqueous phase. In this study, an ionic liquid (IL) was used as the functional monomer and functionalized P25@IL heterojunction molecular imprinted photocatalytic nanoreactor, referred to as imprinted P25@IL nanoreactor, were prepared via the aqueous-phase microwave polymerization strategy. Imidazole-based IL cations can provide π electron clouds, and side chains are easily functionalized and modified, resulting in strong interactions such as π-π and ion dipoles being formed between IL and levofloxacin hydrochloride (LEV), which can overcome the interference of water molecules and achieve better selective adsorption and degradation of LEV in aqueous medium. The selectivity coefficient of imprinted P25@IL nanoreactor relative to P25 and functionalized P25@IL heterojunction molecular non-imprinted photocatalyst (non-imprinted P25@IL photocatalyst) were 2.69 and 2.26, respectively. More importantly, with the formation of IL-P25 heterojunction and surface imprinted layer, the photocatalytic performance of imprinted P25@IL nanoreactor was 2.33 times higher than that of P25. Our findings offer a novel approach to the synthesis of water-soluble functional monomers and the aqueous-phase synthesis of molecular imprinted photocatalytic materials.