PhotoresponsiveTrifluoroacetic Acid Vapor and PhotocatalyticPurification of Dye and Antibiotic Wastewater by a Tetraphenylethylene-BasedLayered Dynamic Metal–Organic Framework

Abstract Introducing aggregation-induced emission luminogens (AIEgens) with dynamic molecular rotor modules into luminescent metal–organic frameworks (MOFs) to construct dynamic intelligent luminescent materials has become a method for synthesizing artificial intelligence color-changing materials. In this work, two-dimensional layered Ln-MOFs (Eu-TPE and Gd-TPE) with a high degree of molecular rotor freedom in the pores were synthesized using 4,4′-(2,2-diphenylethylene-1,1-diyl)benzoic acid (TPE-2COOH) containing two coordination sites as organic linking pillars. The photoluminescence intensity of Eu-TPE exhibits a dual-segment characteristic, decreasing rapidly in the low-temperature region and slowly in the high-temperature region. Benefiting from the significant heavy-atom effect of Gd3+ ions and the good conjugated structure of TPE-2COOH, Gd-TPE exhibits excellent reactive oxygen species (ROS) generation capacity under light irradiation. Under low-power light irradiation (60 mW·cm–2), Gd-TPE can efficiently degrade a variety of colored dyes and antibiotics in a short time, with degradation rates of 0.034, 0.033, 0.032, and 0.037 min–1, respectively. Furthermore, the presence of numerous free molecular rotor modules within the Eu-TPE channels enables rapid, convenient, and visualized photoresponse to trifluoroacetic acid (TFA) vapor. The entry of TFA vapor into the Eu-TPE channels reduces the mobility and increases the tortuosity of the molecular rotor modules, resulting in significantly enhanced fluorescence of Eu-TPE through restricted intramolecular emission.