Magnetic metal organic frameworks (MOFs) composite for removal of lead and malachite green in wastewater

Abstract

We designed and synthesized a magnetic metal organic frameworks (MOFs) composite, Cu-MOFs/Fe3O4 as the adsorbent for removal of lead (Pb(II)) and malachite green (MG) in wastewater. This Cu-MOFs/Fe3O4 can be easily prepared by in-situ growth of Cu-MOFs with doping Fe3O4 nanoparticles. The prepared Cu-MOFs/Fe3O4 composite was well characterized by SEM, XRD, and FTIR spectra. The adsorption experiments found that Cu-MOFs/Fe3O4 can serve as adsorbent for removal of Pb(II) and MG simultaneously. The adsorption capacities were found to be 113.67mg/g for MG and 219.00 mg/g for Pb 2+ , respectively, which are significantly higher than reported materials. Adsorption isotherm, kinetics and recyclability of Cu-MOFs/Fe3O4 for removal of Pb(II) and MG were then studied. Adsorption of Pb(II) and MG exhibited Freundlich adsorption isotherm model, with the adsorption kinetics of available second-order kinetic. Physical adsorption for MG and chemical adsorption for Pb(II) were confirmed by Dubinin-Radushkevich (D-R) isothermal adsorption model. The adsorption of Pb(II) and MG in real water samples were then studied. The Fe3O4/Cu-MOFs was found to be recyclable for removal of Pb(II) and MG, can be explored as the potential adsorbent for waste water treatment.

Graphene Paper with Sharp‐edged Nanorods of Fe−CuMOF as an Excellent Electrode for the Simultaneous Detection of Catechol and Resorcinol

“…The peak at 25.4°, corresponding to the characteristic crystal diffraction of the graphene structure (002) was observed in the XRD spectrum of rGO paper (JCPDS card no 4–0783). In XRD data of Fe−CuMOF composite powder, the peaks at about 42.9°, and 58.1° correspond to the (400), and (511) structure of Fe 3 O 4 nanoparticles, respectively (JCPDS card no 99–0073 and 43.5°, 50.2° and 74.5° correspond to the (111), (200) and (220) structure of Cu, respectively (JCPDS card no 04–0836) . The formation of diffraction peaks of both Fe 3 O 4 and Cu in the XRD spectrum of Fe−CuMOF composite powder was supported the successful preparation of Fe−CuMOF composite structure.…”

“…In Figure S3.a, it was determined that Fe 3 O 4 nanoparticles had a size ranging between 10 and 80 nm. In XRD data of Fe 3 O 4 (Figure S3.b), the peaks at about 30°, 36°, 44°, 53°, 57°, and 63° correspond to the (220), (311), (422), (511), and (400) structure of Fe 3 O 4 (JCPDS: 99‐0073), respectively , indicates that Fe 3 O 4 nanoparticles have been successfully prepared. Crystallite size of Fe 3 O 4 nanoparticles was calculated by applying Scherrer's equation: D=Kλ/βcosθ, where D is the average diameter, K is Sherrer constant, λ is ray wavelength (0.15406 nm), β is the peak width of half‐maximum, and θ is the Bragg diffraction angle.…”

“…After stirring for 10 min, 1.2 g Cu(NO 3 ) 2 in 15 mL ethanol was added to the mixture. This mixture was then transferred into Teflon‐lined autoclave for heating at 120 °C for 12 h. The products were then collected, and washed with ethanol‐water for several times and dried in air to obtain Fe−CuMOF composite . The schematic illustration of the synthesis of Fe 3 O 4 particles and Fe−CuMOF composite was presented in Figure S1.…”

Highly efficient removal of toxic lead ions from aqueous solutions using a new magnetic metal‐organic framework nanocomposite

“…From the slope and intercept of the plot of log K c versus 1/T (Figure 12a), the enthalpy (ΔH ) and entropy (ΔS ) at 288-318 K can be obtained. [5] The adsorption system is influenced by the free active sites on the adsorbent and other factors of the adsorption medium such as ion concentration, solution pH, temperature, etc. The negative amount of free energy change (ΔG ) for the adsorption of Pb(II) onto Fe 3 O 4 -NHSO 3 H@H-KUST-1 at the studied range of temperature indicates the spontaneous nature of the adsorption process.…”

“…The high porosity, expansion and and contraction of structurally flexible MOFs provides different properties and applications viewpoints including structural characterization, crystal engineering, adsorption-separation applications of gas, [1] as well as the removal of pollutants such as dyes, [2][3][4] heavy metals, [5,6] toxic compounds, [7,8] and pesticides [9][10][11] from the environment. The high porosity, expansion and and contraction of structurally flexible MOFs provides different properties and applications viewpoints including structural characterization, crystal engineering, adsorption-separation applications of gas, [1] as well as the removal of pollutants such as dyes, [2][3][4] heavy metals, [5,6] toxic compounds, [7,8] and pesticides [9][10][11] from the environment.…”