Structural Design of Low Toxicity Metal–Organic Frameworks for Multifunction Detection of Organic and Inorganic Contaminants from Water

Metal–organic frameworks (MOFs)-based sensors for monitoring toxic substances in wastewater have attracted great attention due to the efficient and reliable performance. Here, we has synthesized two novel zinc-based MOFs [Zn­(ttb)₂(H₂O)₂]_n (Zn1-ttb) and {[Zn­(ttb)₂]·0.5CH₃CN}_n (Zn2-ttb) through changing the polarity of reaction solvents and finally obtained target 2D MOF material [Zn­(ttb)­(bdc)_0.5]_n(Zn3-ttb-bdc) by successfully introducing an ancillary ligand H₂bdc (Httb = 1-(triazo-1-ly)-4-(tetrazol-5-ylmethyl)­benzene, H₂bdc = 1,4-benzenedicarboxylic acid). As-prepared Zn3-ttb-bdc exhibits high water and chemical stability as well as excellent fluorescence property. Due to the −COOH binding sites from H₂bdc, Zn3-ttb-bdc shows high sensitivity and a rapid luminescent response to a representative organic micropollutant trinitrophenol (TNP) and inorganic pollutants (Fe³⁺ and Cr₂O₇^2–) in wastewater. The mechanisms of multifunctional detection abilities of Zn3-ttb-bdc toward different types of pollutants are further studied. This work presents the structural design in preparing MOF materials for multifunctional detection performance, thus opening new perspectives for emerging MOF-based sensors as environmental monitors.