Reda M. Abdelhameed

Enhanced Photocatalytic Activity of MIL‐125 by Post‐Synthetic Modification with CrIII and Ag Nanoparticles

NH2 -MIL-125, [Ti8 O8 (OH)4 (bdc-NH2 )6 ] (bdc(2-) =1,4-benzene dicarboxylate) is a highly porous metal-organic framework (MOF) that has a band gap lying within the ultraviolet region at about 2.6 eV. The band gap may be reduced by a suitable post-synthetic modification of the nanochannels using conventional organic chemistry methods. Here, it is shown that the photocatalytic activity of NH2 -MIL-125 in the degradation of methylene blue under visible light is remarkably augmented by post-synthetic modification with acetylacetone followed by Cr(III) complexation. The latter metal ion extends the absorption from the ultraviolet to the visible light region (band gap 2.21 eV). The photogenerated holes migrate from the MOFs valence band to the Cr(III) valence band, promoting the separation of holes and electrons and increasing the recombination time. Moreover, it is shown that the MOFs photocatalytic activity is also much improved by doping with Ag nanoparticles, formed in situ by the reduction of Ag(+) with the acetylacetonate pendant groups (the resulting MOF band gap is 2.09 eV). Presumably, the Ag nanoparticles are able to accept the MOFs photogenerated electrons, thus avoiding electron-hole recombination. Both, the Cr- and Ag-bearing materials are stable under photocatalytic conditions. These findings open new avenues for improving the photocatalytic activity of MOFs.

Cu–BTC@cotton composite: design and removal of ethion insecticide from water

Pesticide removal from wastewater is of significant general benefit to protect of humans from the effect of pollution. Current study offers excellent material for organophosphate insecticide pollution remediation based on metal–organic frameworks (MOFs). A facile method was used to functionalize cotton fabric by assembly with Cu–BTC MOFs. The so-prepared Cu–BTC@cotton composite was characterized by X-ray diffraction, infrared spectroscopy, elemental analysis, and electron microscope. Cu–BTC was successfully bonded with cotton fabrics through interaction between Cu and cellulose functional groups. Adsorption of ethion as organophosphorus insecticide onto Cu–BTC@cotton composite was systematically studied. Binding sites of composite represented in cellulose functional groups and Cu of MOF were both linked with ethion via sulfur. The equilibrium adsorption isotherm proved that the adsorption of ethion insecticide was fitted well to the Langmuir model. The maximum sorption capacity of Cu–BTC@cotton composite reached 182 mg g−1 and the removal percent of ethion exceeded 97%. Furthermore, Cu–BTC@cotton composite is very stable and can be easily recycled using a simple organic solvent. After recycling five times, the adsorption efficiency of Cu–BTC@cotton composite was still very good and surpassing 85%. Therefore, Cu–BTC@cotton is a perfect sorbent to remove insecticides from wastewater with excellent efficiency.

Engineering lanthanide-optical centres in IRMOF-3 by post-synthetic modification

The use of the post-synthetic modification of metal–organic frameworks is a recent strategy for engineering the coordination sphere of lanthanide cations and optimizing the light-emission properties of organic–inorganic hybrid materials. Here, IRMOF-3 was modified with 2-chloroacetic acid, glyoxylic acid, diethyl (ethoxymethylene)malonate and methyl vinyl ketone (vapour) and characterized by elemental analysis, solution and solid-state NMR, Fourier transform infrared spectroscopy, powder X-ray diffraction and scanning electron microscopy. The yields of the amino groups conversion were, respectively, 100% (IRMOF-3-CA), 75% (IRMOF-3-Gl), 80% (IRMOF-3-EM), and 76% (IRMOF-3-MVK). The reductive amination of IRMOF-3-Gl was carried out using sodium triacetoxyborohydride. The modified IRMOF-3 pendant groups were used to coordinate Eu3+ and Nd3+ and generate infrared (and visible) light emission.

Antimosquito Activity of a Titanium–Organic Framework Supported on Fabrics

Waste swamps, stagnant water, and poor hygiene practices result in the proliferation of mosquitoes that may cause transmissible and infectious diseases such as malaria, typhoid, cholera, and Zika virus sickness. It has been shown that composites of the traditional natural fibers cotton, viscose, and linen and a Ti-bearing metal-organic framework, NH2-MIL-125, are very effective against mosquitoes in the absence of any conventional insecticides. In our study, prior to coating with NH2-MIL-125 crystals, the fabrics were modified with 3-glycidyloxypropyltrimethoxysilane. The composite materials were characterized by powder X-ray diffraction, UV-vis spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy with energy-dispersive X-ray spectroscopy analysis. The latter, in particular, has shown the uniform coating of the fabrics with NH2-MIL-125 crystals. The modified fabrics have excellent antimosquito properties, attracting and killing them.

Figuration of Zr-based MOF@cotton fabric composite for potential kidney application

Hemodialysis is one of the earliest artificial kidney systems, which removes uremic toxins through using a semipermeable porous membrane. Current report focuses on designation of metal organic framework (MOF) based zirconium@cotton fabric composite and its application in kidney dialysis. UiO-66-(COOH)2 as MOF material was directly grown within cotton fabric. Fabric was firstly reacted with benzene tetra carboxylic acid forming ester and then Zr was interacted with the free carboxylic groups in the formed ester to produce UiO-66-(COOH)2@cotton fabric composite. The obtained composite was characterized by using electron microscope, X-ray diffraction, infrared spectroscopy and colorimetric data. After modification with MOF, fabric was acquired yellowish color. The prepared composite was used in potential kidney application through studying the removal of creatinine from mimic blood. The maximum adsorption capacity of creatinine was 113.6 and 192.3-212.8 mg/g for pristine fabric and UiO-66-(COOH)2@fabric composite, respectively. From adsorption data, creatinine adsorption onto composite was followed to pseudo-second order kinetic model and Langmuir isotherm profile. After three regeneration cycles, the applied composite still achieved substantial adsorption capacity by removing of 82% from creatinine. UiO-66-(COOH)2@cotton could be considered as successful adsorbent capable of removing creatinine from blood with good reusability, which can be applied in kidney dialysis.

Separation of bioactive chamazulene from chamomile extract using metal-organic framework

HIGHLIGHTSNano‐ Cu‐BTC MOF was synthesized by a novel way using cotton fabric as template.Chamazulene as bioactive compound seperated for the first time using Metal‐Organic Frameworks.The adsorption and desorption of Chamazulene onto Cu‐BTC MOF are studied.Breakthrough experiments in a column was investigated. ABSTRACT Isolation of bioactive compounds from extracts of pharmaceutical plant is very important. In this work, copper benzene‐1,3,5‐tricarboxylate metal organic framework (Cu‐BTC MOF) has been synthesized. It is used in separating of chamazulene from chamomile extract. The Cu‐BTC MOF not only shows good chamazulene adsorption but also maintains good desorption properties. However, the research on this field is still new and the maturation of novel MOFs or the enhancements of known ones are required.The chamomile extract obtained after each stage of the treatments was carefully characterized by thin‐layer chromatography (TLC), Fourier‐transform infrared spectroscopy (FTIR), UV–vis spectrometry and gas chromatography‐mass spectrometry (GC–MS). The morphology and the crystallinity of Cu‐BTC MOF were investigated using scanning electron microscopy (SEM) and powder X‐ray diffraction (PXRD), respectively. Breakthrough experiments in a column was investigated and the data was fitted with Bohart‐Adams model. Monte Carlo simulation was conducted to investigate the preferential adsorption sites of Cu‐BTC for chamazulene molecules.