Facile synthesis of hierarchically structured MIL-53(Al) with superior properties using an environmentally-friendly ultrasonic method for separating lead ions from aqueous solutions

Abstract

The present study aims at investigating sonochemically synthesized MIL-53(Al) and its applications in adsorption lead ions from aqueous solution. XRD, FESEM, BET, and FTIR analyses were employed to identify and characterize MIL-53(Al). The ultrasonic-assisted synthesis procedure results in reducing the synthesis time to 24 h; however, the conventional synthesis of MIL-53(Al) takes 3 days. Applying ultrasonic waves also leads to increase of the specific surface area up to 50% more than that of synthesized by the conventional method, as well as creating the hierarchical MIL-53(Al) structure which reduces the mass transfer limitation of ions into internal micropores. The optimum conditions for removing lead ions are pH of 6, Pb+2 ion concentration of 20 mg/L, contact time of 60 min, adsorbent dose of 0.04 g, and temperature of 318 K with the removal efficiency of 97.63%. The experimental adsorption equilibrium and kinetic data fit the Langmuir isotherm and pseudo-second-order kinetic models, respectively. Moreover, the usage of sonochemically synthesized MIL-53(Al), for the first time as an adsorbent in heavy metal removal points to the great potential of this new environmentally-friendly adsorbent in removing lead ions from aqueous solutions

Preparation of Magnetic MIL-68(Ga) Metal–Organic Framework and Heavy Metal Ion Removal Application

“…Figure S1 illustrates the FT-IR spectra of MIL-68(Ga) and magnetic MIL-68(Ga). Both of the composites had obvious adsorption peaks in a wavelength range of 1700–1400 cm −1 , demonstrating the existence of carbonyl groups [ 38 ]. Moreover, the new band at 580 cm −1 represented the presence of an Fe-O group in magnetic MIL-68(Ga).…”

Selective adsorption of anionic and cationic dyes on mesoporous UiO-66 synthesized using a template-free sonochemistry method: kinetic, isotherm and thermodynamic studies

“… 37 On the other hand, an increase in the mesoporous volume and a decrease in the surface area of the material treated with ultrasonic irradiation can be associated with severe damage to the material. 59 As shown in the XRD pattern of mesoporous UiO-66(U), the crystal structure of mesoporous UiO-66(U) is nearly destroyed owing to collapse. The UiO-66 micropore channel is therefore eliminated.…”

Physicochemical characterization of metal organic framework materials: A mini review

“…1 b) that are not suitable for single crystal XRD. To resolve this, alternatively, their structure is computationally resolved using the data of powder X-ray diffractometers (PXRD) [ 4 , 33 , 34 ]. Practically, micro-size crystals are represented by the patterns of sharp and narrow peaks, whereas the patterns of wide and short peaks are associated with nano-sized crystals.…”