A stable multifunctional cadmium-organic framework based on 2D stacked layers: Effective gas adsorption, and excellent detection of Cr3+, CrO42−, and Cr2O72-

Abstract

Multifunctional metal-organic frameworks incorporated with different applications have drawn great attention in chemistry and material science. Herein, a new luminescent compound with 1D microporous channels, namely [Cd(OBA)(L1).0.75DMA]n (1, H2OBA = 4,4′-oxybis(benzoic acid), L1 = 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole), has been constructed and well explored, which features good thermal and chemical stability. The activated compound 1 with 10.2 Å channels calculated by HK method using N2 adsorption/desorption isotherms at 77 K, reveals a positive CO2 uptake capacity of 68.0 and 40.8 cm3 g−1 at 273 and 298 K, respectively, but it captures a relatively lower amount of CH4 gas under similar atmosphere. Meanwhile, the high H2 capture amount of compound 1 has been demonstrated with 165.2 cm3 g−1 (1.52%) at 1 atm, 77 K. Interestingly, this compound displays a prominently selective and sensitive response to Cr3+, CrO42−, and Cr2O72− in aqueous media. The detection limits of Cr3+, CrO42−, and Cr2O72− are calculated to be 10.25, 0.30, and 9.18 μM, respectively. Moreover, compound 1 can be easily regenerated and reused for detecting CrO42− and Cr2O72− at least three times. Remarkably, the test paper incorporated compound 1 can easily detect these three ions. All these results indicate that compound 1 is a multifunction material with potentials of CO2 selective adsorption and separation, high H2 uptake, high selectivity and sensitivity as well as excellent recyclability for Cr3+, CrO42−, and Cr2O72−.