Mixed matrix membranes containing fluorescent coordination polymers for detecting Cr₂O₇²⁻ with high sensitivity, stability and recyclability

Abstract

Three coordination polymers (CPs) were synthesized by CdII, fluorescent 9,10-di(4-pyridyl)anthracene (dpa), and cyclohexane-1,4-dicarboxylic acid (H2cda), which are [Cd2(dpa)2(cda)Cl2]n (1), [Cd(dpa)2(cda)]n (2) and [Cd(dpa)(cda)(H2O)]n (3). Both 1 and 2 are fluorescent...

A stable 2D luminescent metal–organic framework as a highly sensitive sensor for Fe3+and Cr2O72−/CrO42−in water

“…The limit of detection (LOD) was 4.08 × 10 −6 mol L −1 obtained by using the expression 3 σ / k , where σ is the standard deviation of luminescent intensities of 10 field blanks, and k is the slope. 9–15…”

“…The high quenching efficiencies and K SV values of 1 can also be compared with most of the reported results of MOF-based Cr 2 O 7 2− /CrO 4 2− sensors (Tables S5 and S6†). 11–15…”

“…9,10 On the other hand, the two inorganic oxygenated acid CrO 4 2− and Cr 2 O 7 2− ions are vital oxidants in industry and agriculture, but they are harmful for the environment and cause adverse effects for the human body, such as allergic reactions and cancer even in a low concentration. 11–15 Therefore, different types of MOFs have been synthesized and employed for the detection of Fe 3+ and/or CrO 4 2− /Cr 2 O 7 2− ions over the past few years, 11–15 but most of the documented MOFs are not stable in the aqueous system, which means those MOF materials are hardly used in real life. Therefore, it is significant to explore highly stable MOFs for the detection of Fe 3+ and CrO 4 2− /Cr 2 O 7 2− ions in the aqueous system.…”

Cationic Metal–Organic Framework-Based Mixed-Matrix Membranes for Fast Sensing and Removal of Cr2O72− Within Water

“…However, to the best of our knowledge, only two MMMs have been developed for the fluorescence sensing of Cr 2 O 7 2− in aqueous solution (Qin et al, 2021;Xu et al, 2021), MMMs for the removal and sensing of Cr 2 O 7 2− simultaneously within water have not been discussed yet. [Eu 7 (mtb)…”

“…However, to the best of our knowledge, only two MMMs have been developed for the fluorescence sensing of Cr 2 O 7 2− in aqueous solution ( Qin et al, 2021 ; Xu et al, 2021 ), MMMs for the removal and sensing of Cr 2 O 7 2− simultaneously within water have not been discussed yet. [Eu 7 (mtb) 5 (H 2 O) 16 ]·NO 3 8DMA·18H 2 O (Eu-mtb, H 4 mtb = 4-[tris(4-carboxyphenyl)methyl]benzoic acid)) is a hydrolytically stable cationic MOF that has been reported to have the lowest detection limit for Cr 2 O 7 2− ( Liu et al, 2017 ).…”