Green synthesis and evaluation of an iron-based metal–organic framework MIL-88B for efficient decontamination of arsenate from water

Abstract

Iron-containing metal-organic frameworks (MOFs) have gradually emerged as environmentally benign alternatives for reducing the levels of environmental contamination because of their advantages, such as readily obtained raw materials with low cost, nontoxic metal source with good biocompatibility, and distinguished physicochemical features e.g., high porosity, framework flexibility, and semiconductor properties. In this study, we reported an innovative strategy for synthesizing an iron-based MOF, MIL-88B, at room temperature. The novelty of this strategy was the use of ethanol as solvent and the pretreatment of dry milling with neither the bulk use of a toxic organic solvent nor the addition of extremely dangerous hydrofluoric acid or strong alkali. The synthesized MIL-88B(Fe) was evaluated as a sorbent for removing arsenate in water and it exhibited high adsorption capacity (156.7 mg g) at a low dosage. The removal capacity of trace arsenate on MIL-88B(Fe) was 32.3 mg g at a low equilibrium concentration (6.4 μg L), which satisfied the arsenic threshold for drinking water. The results of Fourier transform infrared and X-ray photoelectron spectroscopy indicated that the As(v) molecules bonded with the oxygen molecules, which were coordinated with FeO clusters in the framework. This work presented the potential use of the up-scaled MIL-88B as an excellent sorbent for purifying arsenate-contaminated water.

Engineering MIL‐88B crystallites for enhanced H 2 uptake capacity: The role of ultramicropores

“…The highest H 2 adsorption capacity (0.47‐wt% H 2 sorption capacity at 7.6 bar and 298 K) belongs to MIL‐88B‐3 (MIL‐88B‐3), which possesses the highest fraction (89%) and volume (0.22 cm 3 /g) of ultramicropores. Additionally, a BET surface area 2.11 and 2.74 times higher than those of reported MIL‐88Bs has been achieved . Moreover, by the formation and control of hierarchical pores, the fraction of ultramicropores was increased to 89%, which results measured H 2 adsorption capacities to increase by a factor of 1.96 (0.47 wt% at 7.6 bar and 298 K).…”

“…Additionally, a BET surface area 2.11 and 2.74 times higher than those of reported MIL-88Bs has been achieved. 30,31 Moreover, by the formation and control of hierarchical pores, the fraction of ultramicropores was increased to 89%, which results measured H 2 adsorption capacities to increase by a factor of 1.96 (0.47 wt% at 7.6 bar and 298 K). This measured H 2 adsorption capacity (at 7.6 bar and 298 K) of MIL-88B-3 is higher than some of those reported and commercially available MOFs, which is thought to be a consequence of its high fraction of pores with pore diameters of 0.6 nm (89% of the total pore volume was formed of pores with 0.6-nm diameter).…”

“…MIL‐88B crystallites were synthesized via a perturbation assisted nanofusion synthesis strategy and the fraction and the volume of textural pores were controlled by the iron to terephthalic acid (TPA) ratio (1, 3, and 5). By the control over textural porosity via Fe:TPA ratio, an ultramicroporous MOF structure (pores with pore diameters of 0.6 nm dominated the pore structure) with a Brunauer‐Emmett‐Teller (BET) surface area 2.11 and 2.74 times higher than those of reported MIL‐88Bs has been achieved . More importantly, the measured H 2 adsorption capacity at 298 K has been enhanced by a factor of 1.96.…”

“…By the control over textural porosity via Fe:TPA ratio, an ultramicroporous MOF structure (pores with pore diameters of 0.6 nm dominated the pore structure) with a Brunauer-Emmett-Teller (BET) surface area 2.11 and 2.74 times higher than those of reported MIL-88Bs has been achieved. 30,31 More importantly, the measured H 2 adsorption capacity at 298 K has been enhanced by a factor of 1.96. Our results reveal that H 2 adsorption capacity of porous structures (at 298 K and pressures lower than 10 bar) are highly dependent on (a) the presence of ultramicropores; (b) high fraction of ultramicropores through the whole pore size distribution; and (c) the volume of ultramicropores.…”

A new one‐dimensional coordination polymer synthesized from zinc and guanazole: Superior capture of organic arsenics

“…[ 61 ] As the previous reports indicate, the new bands at 897, 850, and 781 cm −1 ( BUC‐70 after adsorbing p ‐ASA) and 897, 851, and 781 cm −1 ( BUC‐70 after adsorbing ROX) might be attributed to the formation of Zn–O–As bonds. [ 62–64 ] The small peak at 656 cm −1 (after adsorption of p ‐ASA and ROX) might be attributed to the asymmetric stretching of As–OH. [ 65 ] The elemental mapping results (Figure 10) confirmed the presence of arsenic on BUC‐70 after the adsorption test.…”