Showing papers by "Shaeel A. Al-Thabaiti published in 2022"

Synthesis and characterization of hexagonal Mg Fe layered double hydroxide/grapheme oxide nanocomposite for efficient adsorptive removal of cadmium ion from aqueous solutions: Isotherm, kinetic, thermodynamic and mechanism

Abstract: Heavy metal pollution in water is a major concern due to its bioaccumulation, non-biodegradability, and high toxicity. Long-term cadmium (Cd(II)) ion exposure could have an adverse impact on human health. Because, natural water bodies contain Cd(II) pollution at low concentrations, the treatment of Cd(II)-polluted water should be treated as micro-polluted water. It is critical to develop an effective water purification procedure to remove Cd(II) from micro-polluted water. In the present research, Mg Fe binary layered hydroxide/graphene oxide (Mg Fe LDH/GO) nanocomposite was synthesized, characterized and used for efficient Cd(II) adsorption. The adsorption process was investigated in terms of pH influence, kinetic behavior, isotherm equilibrium curves, and estimation of thermodynamic parameters. The characterization results showed that Mg Fe LDH/GO, which is composed of crystalline Mg Fe binary hydroxide and amorphous GO structures, has a considerable surface area (223 m 2 /g) and has a plate-like hexagonal structure with even forms and lamellar aggregates. Cd(II) adsorption was favoured on the Mg Fe LDH/GO surface in neutral circumstances at 25 °C. The pseudo-second-order kinetic behavior was adequately described, although the isotherm equilibrium curves fitted the Langmuir isotherm, with a high maximum uptake capacity of 174.83 mg/g. Chemisorption-controlled spontaneous and endothermic reactions occurred, which was confirmed by thermodynamic studies. Further, the surface interaction mechanism was investigated using the XPS analysis of spent catalyst. The Mg Fe LDH/GO nanocomposite is efficient to treat Cd(II) with a removal percentage of 99%. It can be reused more than four times without losing its original capacity and stability. Overall, the Mg Fe LDH/GO nanocomposite exhibited high potential to be utilized as an adsorbent for the removal of pollutants from actual contaminated water samples. • Facile synthesized and characterized hexagonal Mg Fe LDH/GO nanocomposite. • Mg Fe LDH/GO shows a high adsorptive removal capacity, 174.83 mg/g. • Evaluated the applicability of Mg Fe LDH/GO for real water systems. • Environment & economic feasibility and stability of Mg Fe LDH/GO well studied.

Twin-free, directly synthesized MFI nanosheets with improved thickness uniformity and their use in membrane fabrication

Abstract: Zeolite nanosheets can be used for the fabrication of low-defect-density, thin, and oriented zeolite separation membranes. However, methods for manipulating their morphology are limited, hindering progress toward improved performance. We report the direct synthesis (i.e., without using exfoliation, etching, or other top-down processing) of thin, flat MFI nanosheets and demonstrate their use as high-performance membranes for xylene isomer separations. Our MFI nanosheets were synthesized using nanosheet fragments as seeds instead of the previously used MFI nanoparticles. The obtained MFI nanosheets exhibit improved thickness uniformity and are free of rotational and MEL intergrowths as shown by transmission electron microscopy (TEM) imaging. The nanosheets can form well-packed nanosheet coatings. Upon gel-free secondary growth, the obtained zeolite MFI membranes show high separation performance for xylene isomers at elevated temperature (e.g., p-xylene flux up to 1.5 × 10−3 mol m−2 s−1 and p-/o-xylene separation factor of ~600 at 250°C).

Fe3O4@date seeds powder: A sustainable nanocomposite material for wastewater treatment

Abstract: This study reports synthesis and utilization of Fe 3 O 4 @date seeds powder to remove methylene blue from water. The adsorbent has been produced by a simple co-precipitation method, in which Fe 3 O 4 nanoparticles are grown on date seeds powder. Different chemical functional groups were found on surface of the prepared bio-adsorbent. The size of the grown Fe 3 O 4 nanoparticles was observed to be around 5 nm and confirmed their magnetic character via VSM measurement. Several non-linear adsorption isotherm models such as Langmuir, Freundlich, and Redlich-Peterson were obtained for methylene blue dye adsorption, and it was observed that the Freundlich isotherm is the best fitted model. The monolayer adsorption capacity calculated from Langmuir isotherm was 76.652 mg g −1 at 27 °C. The kinetic models (pseudo first order and pseudo second order) were also studied for methylene blue adsorption and the pseudo second order is the best fitted model in the present investigation. The methylene blue adsorption isotherm and kinetic study suggested that the current adsorption process was carried out by electrostatic interactions between the functional groups on the surface of the Fe 3 O 4 @date seeds powder and the dye, and the rate determining step was intraparticle diffusion. This entire study has been systematically explained through comparative study of literature. This study proves that the developed adsorbent is bio-degradable, inexpensive, and efficient for dye removal, which recommends increasing the production of natural bio-adsorbents in the future for water purification.

C–H activation: A strategic approach toward lactams using transition metals

Abstract: The presence of lactam motif in surrounding biological and pharmaceutical arenas themselves calls for an easy and synthetically viable route toward its synthesis. There are multiple ways to achieve molecular targets; however, activating a C–H bond has attracted the chemical community for decades. Recent advances introduce a spectrum of mild routes to activate very inert C–H bonds, and here, it becomes highly important for the manufacturing of lactam moieties. Even the activation of distal-located C–H bonds can generate a chance of synthesizing macromolecules. In this review, we discuss the ways in which C–H activation can help to create molecular complexities containing lactam skeleton.

C−H Methylation Using Sustainable Approaches

Abstract: C−H methylation of sp2 and sp3 carbon centers is significant in many biological processes. Methylated drug candidates show unique properties due to the change in solubility, conformation and metabolic activities. Several photo-catalyzed, electrochemical, mechanochemical and metal-free techniques that are widely utilized strategies in medicinal chemistry for methylation of arenes and heteroarenes have been covered in this review.

One-Pot Facile Synthesis of CuO–CdWO4 Nanocomposite for Photocatalytic Hydrogen Production

Abstract: Hydrogen (H2) is a well-known renewable energy source that produces water upon its burning, leaving no harmful emissions. Nanotechnology is utilized to increase hydrogen production using sacrificial reagents. It is an interesting task to develop photocatalysts that are effective, reliable, and affordable for producing H2 from methanol and acetic acid. In the present study, CuO, CdWO4, and CuO–CdWO4 nanocomposite heterostructures were prepared using a cost-efficient, enviro-friendly, and facile green chemistry-based approach. The prepared CuO, CdWO4, and CuO–CdWO4 nanocomposites were characterized using X-ray diffraction pattern, Fourier-transform infrared spectroscopy, diffuse reflectance ultraviolet–visible spectroscopy, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction (SAED) pattern, N2 physisorption, photoluminescence, and X-ray photoelectron spectroscopy techniques. The synthesized photocatalysts were utilized for photocatalytic H2 production using aqueous methanol and acetic acid as the sacrificial reagents under visible light irradiation. The influence of different variables, including visible light irradiation time, catalyst dosage, concentration of sacrificial reagents, and reusability of catalysts, was studied. The maximum H2 was observed while using methanol as a sacrificial agent over CuO–CdWO4 nanocomposite. This enhancement was due to the faster charge separation, higher visible light absorption, and synergistic effect between the CuO–CdWO4 nanocomposite and methanol.