Ebrahim Mahmoudi

Chemical Vapor Deposition of Methane in the Presence of Cu/Si Nanoparticles as a Facile Method for Graphene Production

This study reports on a facile, scalable, and economical method for the synthesis of graphene sheets via catalytic decomposition of methane. The catalyst was prepared by a simple sol–gel method. In this method, copper was doped by a silicon dioxide substrate to prepare a novel catalyst to be used in the chemical vapor deposition (CVD) process. The CVD method has a remarkably high capacity as well as efficiency potentials in terms of high-yield graphene production with superior morphology. Few-layered graphene (FLG) sheets were produced successfully under atmospheric pressure. The X-ray crystallography patterns confirmed the formation of graphene sheets. The obtained graphene was characterized by Raman spectroscopy, and the results proved that high quality graphene sheets with an ID/IG ratio of 0.7 were obtained. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) micrographs were also used to investigate the shape and the morphology of the prepared FLG. The average thickness of the obtained graphene sheets was found to be equal to ˜8 nm using transmission electron microscopy (TEM). XRD, FTIR and XPS spectra were also obtained to confirm the formation of graphene and its nature.

Characterization and Separation Performance of a Novel Polyethersulfone Membrane Blended with Acacia Gum

Novel polyethersulfone (PES) membranes blended with 0.1–3.0 wt. % of Acacia gum (AG) as a pore-former and antifouling agent were fabricated using phase inversion technique. The effect of AG on the pore-size, porosity, surface morphology, surface charge, hydrophilicity, and mechanical properties of PES/AG membranes was studied by scanning electron microscopy (SEM), Raman spectroscopy, contact angle and zeta potential measurements. The antifouling -properties of PES/AG membranes were evaluated using Escherichia coli bacteria and bovine serum albumine (BSA). The use of AG as an additive to PES membranes was found to increase the surface charge, hydrophilicity (by 20%), porosity (by 77%) and permeate flux (by about 130%). Moreover, PES/AG membranes demonstrated higher antifouling and tensile stress (by 31%) when compared to pure PES membranes. It was shown that the prepared PES/AG membranes efficiently removed lead ions from aqueous solutions. Both the sieving mechanism of the membrane and chelation of lead with AG macromolecules incorporated in the membrane matrix contributed to lead removal. The obtained results indicated that AG can be used as a novel pore-former, hydrophilizing and antifouling agent, as well as an enhancer to the mechanical and rejection properties of the PES membranes.

Synthesis of Iron Oxide Nanoparticles to Enhance Polysulfone Ultrafiltration Membrane Performance for Salt Rejection

Synthesis of Iron Oxide Nanoparticles to Enhance Polysulfone Ultrafiltration Membrane performance for Salt Rejection Muneer M. Ba-Abbad*, Abdul Wahab Mohammad, Mohd S. Takriff, Rosiah Rohani, Ebrahim Mahmoudi, Khalefa A. Faneer, Abdelbaki Benamo Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia. Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia. Gas Processing Centre, Qatar University, P. O. Box 2713 Doha, Qatar. Department of Chemical Engineering, Faculty of Engineering and Petroleum, Hadhramout University of Science &Technology, Mukalla, Hadhramout, Yemen. muneer711@gmail.com

Synthesis and characterization of Sm3+-doped ZnO nanoparticles via a sol–gel method and their photocatalytic application

Spherical ZnO nanoparticles doped by samarium ions were successfully synthesized via a simple sol–gel method. The structures, morphologies, optical properties and surface areas were investigated for all samples using specific characterization methods. The hexagonal wurtzite structure of ZnO and samarium-doped ZnO nanoparticles were determined. The results obtained showed that the sizes of samarium-doped ZnO nanoparticles decreased with increasing samarium ion concentration. It was noticed that in the presence of samarium ions, the band gap slightly changed from the 3.198 eV of ZnO to 3.288 eV for samarium-doped ZnO with enhanced absorption in the UV region. This can be attributed to the transition of electrons from the conduction band to the acceptor energy level of samarium. The XPS results of samarium-doped ZnO, showed that only one oxidation state of samarium, with good incorporation into the ZnO matrix, was presented, with no peak of samarium oxide. The surface areas analyses showed that higher surface areas were obtained for samarium-doped ZnO, which is attributed to the smaller size of the particles. The photocatalytic degradation of 2-chlorophenol was investigated under sunlight in presence of ZnO and samarium-doped ZnO nanoparticles. A higher performance of samarium-doped ZnO for photocatalytic degradation of 2-chlorophenol at 0.50 wt.% was observed, compared to pure ZnO nanoparticles under the same experimental conditions.Graphical abstract