Dual-Functional Indium–Organic Framework for Acetylene Purification and Fluorescence Detection of Fe3+ and Cr2O72– in Water

Metal–organic frameworks (MOFs) have demonstrated considerable research value in the fields of gas adsorption/separation and fluorescence sensing. In this work, a novel indium-based MOF, namely JLU-MOF219 ([In(TCPQ)0.5(HCOO)(DMF)]·DMF), was synthesized using 4,4′,4″,4‴-(quinoxaline-2,3,5,8-tetrayl)tetrabenzoic acid (H4TCPQ) as the organic ligand and In(NO3)3·4H2O as the metal source. JLU-MOF219 possesses a microporous framework and good stability, integrating dual functionalities of gas separation and fluorescence detection. Benefiting from this structural advantage, JLU-MOF219 exhibits notable C2H2 adsorption capacity and high isosteric heat of adsorption, as well as considerable selectivity for C2H2/CO2 and C2H2/CH4. Dynamic breakthrough experiments further verify the practical feasibility of JLU-MOF219 for C2H2 purification. Additionally, benefiting from the aggregation-induced emission effect of H4TCPQ ligand, JLU-MOF219 displays prominent fluorescence properties. It can sensitively detect trace Fe3+ and Cr2O72– in aqueous media via the fluorescence quenching effect, with excellent anti-interference ability against competing ions. With high Ksv values, low limits of detection, and good cyclic stability, JLU-MOF219 can serve as a promising fluorescence sensor for monitoring water pollutant ions.