Fabrication of a Cd(ii) metal-organic framework as a dual functional material: efficient iodine capture and selective adsorption of a cationic dye

Effectively capturing radioiodine that is created or released as a result of nuclear fission is crucial for environmental protection. Metal-organic frameworks (MOFs) may be useful materials in this case to aid with the problematic environmental issue. The solvothermal reaction of Cd(ii) salt with rigid terephthalic acid (H(2)tpa) and 1,2,4-triazole (Htz) builds a novel MOF, [Cd-2(tpa)(tz)(2)(DMF)(2)] (FV-1). According to single crystal XRD, FV-1 has a 3D framework with a 3,4-connected rare dmc topological network with the Schlafli point symbol {4 center dot 8(2)}{4 center dot 8(5)}. The as-prepared MOF was meticulously characterized, and its iodine adsorption in the vapour and solution phases was also examined by UV-vis spectroscopy, with the adsorption capacity being extremely high. FV-1 has a maximum sorption capacity of around 0.554 and 0.301 g g(-1) in the vapour and solution phases, respectively, with a recyclability of up to four cycles. Iodine binds to the MOF in the forms of I-2 and I-3(-) species, according to XPS and Raman spectra. Interestingly, DFT studies on iodine sorption to study the mechanism of binding with FV-1 prove that along with other interactions, the OMIDLINE HORIZONTAL ELLIPSISI interaction predominates to result in high uptake of iodine. Moreover, a cationic dye, methylene blue (MB), can be very effectively and selectively adsorbed and separated (at pH = 7 and room temperature) by FV-1, and the MOF retains the same adsorption capacity even after repeated cycles. Thus, the present MOF acts as a dual functional material for higher iodine uptake and efficient cationic dye adsorption.

Automated summary

Metal-organic frameworks (MOFs), specifically FV-1, demonstrate high iodine adsorption capacity in both vapor and solution phases with excellent recyclability. Additionally, FV-1 can effectively adsorb and separate cationic dyes. This research is of great importance for environmental protection and resource recovery.