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Mesoporous silica SBA-15 grafted with benzene-1,3,5-triamido-tetraphosphonic acid (SBA-15-BTATPA) was synthesized. After detailed characterization of the material using various analytical instrumentation, it was applied for the recovery of Nd 3+ as a function of the contact time, ion concentration, and pH. The adsorption equilibria and kinetics were also examined. Under the optimal conditions, adsorption equilibrium was reached within 60 min of contact time, and the adsorption capacity of Nd 3+ at room temperature and pH 6 was 129.8 mg g −1 , which was higher than that by other rare earth element (REE) ions tested for comparison (Y 3+ , La 3+ , and Ce 3+ ). The adsorbent showed excellent distribution coefficient for Nd 3+ greater than 1.0 × 10 5 mL/g. The preferential order of adsorption in the ion mixture with equal ion concentrations was Y 3+ >Nd 3+ >Ce 3+ >La 3+ , which followed the sequence of their decreasing atomic size and increasing stability constant. The competing adsorption by transition metal ions, such as Cu 2+ , Ni 2+ , Co 2+ , and Zn 2+ , on the REEs recovery was negligible (<2%). The observed adsorption isotherms could be fitted well to a Langmuir model (correlation factor R 2 > 0.99), whereas the adsorption kinetics could be described satisfactorily by a pseudo second order kinetic model. The material was reusable for up to 5 consecutive times with only a slight decrease in adsorption capacity. [ABSTRACT FROM AUTHOR]

A densely-packed IRMOF-3 membrane (S-IRMOF-3(Mem)), ∼55 μm in thickness, on an Al 2 O 3 disc support was prepared via a sonochemical synthesis route, and the optimal fabrication conditions were established. Bare IRMOF-3 particles (S-IRMOF-3(p)) were synthesized independently to analyze the contribution of the Al 2 O 3 support. The overall physicochemical properties of the IRMOF-3 products produced via the sonochemical route were superior to those prepared by microwave heating. The IRMOF-3 materials produced were characterized by XRD, SEM, EDS-mapping, and N 2 adsorption–desorption measurements. S-IRMOF-3(p) exhibited satisfactory CO 2 adsorption capacities (54 mg/g at 298 K/1 bar; 732 mg/g at 298 K/20 bar) and CO 2 /N 2 selectivity (18 at 298 K/1 bar). Both S-IRMOF-3(Mem) and S-IRMOF-3(p) were assessed as a catalyst for a liquid phase Knoevenagel condensation reaction between benzaldehyde and ethyl cyanoacetate. S-IRMOF-3(Mem) and S-IRMOF-3(p) showed comparable conversions (87–89%) with 100% selectivity after a 4 h reaction at 333 K. The heterogeneous nature of the catalyst was confirmed by a hot filtering experiment, and S-IRMOF-3(Mem) could be recovered easily after the reaction and be recycled several times with little change in product yield. [ABSTRACT FROM AUTHOR]

The synthesis of metal-organic frameworks (MOFs) with in-built porphyrin units remains challenging. It takes long synthesis time under carefully controlled reaction conditions, and a mixed-phase with different crystal morphologies is still frequently observed. In this work, Zr-based porphyrinic MOF-525 and MOF-545 in high purity and uniform size were produced through a sonochemical route in 2.5 and 0.5 h, respectively, using zirconyl chloride octahydrate and tetrakis (4-carboxyphenyl) porphyrin. Benzoic acid was used as a modulator for MOF-525, and trifluoroacetic acid for MOF-545. The physicochemical properties of the MOF products were examined by X-ray diffraction, scanning electron microscopy, and N 2 adsorption-desorption isotherms. Additionally, the defect sites in the MOF samples were analyzed by UV–vis spectrometry, thermogravimetric analysis, and inductively coupled plasma mass spectrometer. The sonochemically synthesized MOF samples had more defect sites than the conventionally prepared ones and exhibited improved textural properties. In particular, the MOF-545 had a significantly smaller (ca. 1.0 μ m) particle size than the conventionally prepared sample (ca. 4.8 μ m). The MOF-525 and MOF-545 prepared by the sonochemical route exhibited enhanced hydrolysis of the chemical warfare simulant dimethyl-4-nitrophenyl phosphate (DMNP) and a faster and higher bisphenol-A adsorption than the conventionally prepared MOF samples. MOF-525 and MOF-545 were synthesized through a sonochemical route and tested for the hydrolysis of DMNP and adsorption of BPA. Image 1 • Sonochemical syntheses of zirconium-based porphyrinic MOF 525 and 545 were reported. • High-purity crystals of MOF-525 and MOF-545 were obtained within 2.5 h and 0.5 h, respectively. • These MOFs were tested for the hydrolysis of dimethyl-4-nitrophenyl phosphate (DMNP) and adsorption of bisphenol-A (BPA). • Enhanced performances of these MOFs due to increased defect sites, smaller particles size, and larger BET surface area. [ABSTRACT FROM AUTHOR]