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Prof. Siham Al-Qaradawi is currently a Prof. of organic Chemistry at Qatar University. She received her undergraduate degree in Chemistry with High Honors from Qatar University and her Ph.D. from the University of Reading, the United Kingdom in 1992. She served as Dean for the College of Arts & Sciences for five years. She is currently an elected member in QU faculty Senate, Prof. S. Al-Qaradawi has received the prestigious William Fulbright Award as a visiting Scholar at Temple University, Pennsylvania, the USA in 2010/2011 and the German Award (The German Academic Exchange Service) DAAD in 2003. She had several fellowships at the University of Strathclyde, Glasgow, UK (summer 2000), University of Hamburg, Germany (Summer 2002), University of Hannover, Germany (Summer 2003), and California Institute of Technology, CALTECH, CA, USA (Summer 2013). Prof. Siham Al-Qaradawi is the author of more than 75 academic papers and one patent in organic and nanomaterials synthesis with an H index of 23 and more than 1500 citations. She is the Lead PI in several research grants with more than five million American Dollars. She presented her research outcomes in enormous numbers of international and regional conferences. Her research interest is mainly about Carbon dioxide conversion, Lithium batteri, nanomaterials and Organic Solar Cells. She is a Reviewer for several prestigious Journals like Journal of Molecular Structure, Journal of Molecular Liquids & journal of Spectrochimica Acta.
Metal–organic frameworks (MOFs) have found a potential application in various domains such as gas storage/separation, drug delivery, catalysis, etc. Recently, they have found considerable attention for energy storage applications such as Li- and Na-ion batteries. However, the development of MOFs is plagued by their limited energy density that arises from high molecular weight and low volumetric density. The choice of ligand plays a crucial role in determining the performance of the MOFs. Here, we report a nickel-based one-dimensional metal-organic framework, NiC4H2O4, built from bidentate fumarate ligands for anode application in Li-ion batteries. The material was obtained by a simple chimie douce precipitation method using nickel acetate and fumaric acid. Moreover, a composite material of the MOF with reduced graphene oxide (rGO) was prepared to enhance the lithium storage performance as the rGO can enhance the electronic conductivity. Electrochemical lithium storage in the framework and the effect of rGO on the performance have been investigated by cyclic voltammetry, galvanostatic charge–discharge measurements, and EIS studies. The pristine nickel formate encounters serious capacity fading while the rGO composite offers good cycling stability with high reversible capacities of over 800 mAh g−1.
Shahul Hameed; Shaikshavali Petnikota; Nusyba Hassan; Siham Al-Qaradawi; Zaghib Karim; M. Reddy. Synthesis of Nickel Fumarate and Its Electrochemical Properties for Li-Ion Batteries. Electrochem 2021, 2, 439 -451.
AMA StyleShahul Hameed, Shaikshavali Petnikota, Nusyba Hassan, Siham Al-Qaradawi, Zaghib Karim, M. Reddy. Synthesis of Nickel Fumarate and Its Electrochemical Properties for Li-Ion Batteries. Electrochem. 2021; 2 (3):439-451.
Chicago/Turabian StyleShahul Hameed; Shaikshavali Petnikota; Nusyba Hassan; Siham Al-Qaradawi; Zaghib Karim; M. Reddy. 2021. "Synthesis of Nickel Fumarate and Its Electrochemical Properties for Li-Ion Batteries." Electrochem 2, no. 3: 439-451.
LiNi0.5Mn1.5O4 with a high-voltage spinel structure is a potential cathode material for high-energy lithium-ion batteries (LIBs). Y2O3 coated quasi-spheres of LiNi0.5Mn1.5O4 covered in graphene (LNMO-YO-G) have been synthesized by a microwave-assisted chemical co-precipitation technique. The coating of quasi-spheres with Y2O3 and subsequent wrapping in graphene nanosheets does not modify the bulk structure and inhibits the production of undesirable phases. Thermal analysis indicates that the developed materials demonstrate good thermal stability. The material exhibits an initial capacity of 133 mAh g−1 at the C/10 rate with a capacity retention of 98% after 100 cycles. Remarkably, a discharge capacity of 115 mAh g−1 is achieved in LNMO-YO-G at a 10C rate, reflecting its extraordinary improvement in the rate capability. Furthermore, after 20 cycles at higher temperature (55 °C), the cathode samples exhibit an excellent capacity of 132 mAh g−1. Y2O3 coating reduces the leaching of ions from the electrode, but such coatings reduce the electrical conductivity. Conversely, graphene increases the electrical conductivity, wraps the active particles along an electrically conductive path, and prevents agglomeration. Parasitic reactions are inhibited without compromising electrical conductivity due to the synergistic material design and fast microwave synthesis method. The proposed material synthesis strategy can be effectively extended to other classes of electrode materials to improve their cyclic performance.
Hanan Abdurehman Tariq; Jeffin James Abraham; Aisha Abdul Quddus; Siham AlQaradawi; Ramazan Kahraman; R.A. Shakoor. Graphene wrapped Y2O3 coated LiNi0.5Mn1.5O4 quasi-spheres as novel cathode materials for lithium-ion batteries. Journal of Materials Research and Technology 2021, 14, 1377 -1389.
AMA StyleHanan Abdurehman Tariq, Jeffin James Abraham, Aisha Abdul Quddus, Siham AlQaradawi, Ramazan Kahraman, R.A. Shakoor. Graphene wrapped Y2O3 coated LiNi0.5Mn1.5O4 quasi-spheres as novel cathode materials for lithium-ion batteries. Journal of Materials Research and Technology. 2021; 14 ():1377-1389.
Chicago/Turabian StyleHanan Abdurehman Tariq; Jeffin James Abraham; Aisha Abdul Quddus; Siham AlQaradawi; Ramazan Kahraman; R.A. Shakoor. 2021. "Graphene wrapped Y2O3 coated LiNi0.5Mn1.5O4 quasi-spheres as novel cathode materials for lithium-ion batteries." Journal of Materials Research and Technology 14, no. : 1377-1389.
The idea of lithium (Li)/sodium (Na) incorporated cathodes for both Li/Na-ion batteries has gained significant consideration throughout the past decade. The encouraging performance of various reported Li/Na incorporated cathode systems has the potential to review their exciting developments made so far to clearly understand the effect of numerous variables in improving the electrochemical performance. The current manuscript provides a focused review on the synthesis and electrochemical performance of these Li/Na incorporated cathode materials for Na/Li-ion batteries. Furthermore, the ruling mechanisms affecting the electrochemical performance of Li/Na incorporated cathode materials have been summarized. The majority of the synthesized Li/Na incorporated cathodes demonstrate good electrochemical cyclic stability, capacity retention, rate capability, charge/discharge capacity, etc. Li incorporated Na-based cathodes, show improved performance that can be attributed to the prevention of phase transformation at high voltages and loss of transition metal from the cathode. In the case of Na addition to Li-based cathodes, the Na pillaring effect significantly improves the Li interface layer stability, increases Li-ion diffusion, and retardation of Li and/or transition metal disordering. Various factors affecting the performance of Li/Na incorporated cathode families have been discussed that can be taken into account for development of future novel cathode materials demonstrating decent performance.
Jeffin James Abraham; Christian Randell A. Arro; Hanan Abdurehman Tariq; Ramazan Kahraman; Siham Al-Qaradawi; Talal Mohammed Al Tahtamouni; R.A. Shakoor. Sodium and lithium incorporated cathode materials for energy storage applications - A focused review. Journal of Power Sources 2021, 506, 230098 .
AMA StyleJeffin James Abraham, Christian Randell A. Arro, Hanan Abdurehman Tariq, Ramazan Kahraman, Siham Al-Qaradawi, Talal Mohammed Al Tahtamouni, R.A. Shakoor. Sodium and lithium incorporated cathode materials for energy storage applications - A focused review. Journal of Power Sources. 2021; 506 ():230098.
Chicago/Turabian StyleJeffin James Abraham; Christian Randell A. Arro; Hanan Abdurehman Tariq; Ramazan Kahraman; Siham Al-Qaradawi; Talal Mohammed Al Tahtamouni; R.A. Shakoor. 2021. "Sodium and lithium incorporated cathode materials for energy storage applications - A focused review." Journal of Power Sources 506, no. : 230098.
Catalytic combustion of methane is considered an environmentally friendly route for energy generation owing to the high H/C ratio of methane and low CO2 emissions compared to other hydrocarbons fuels. The utilization of heterogeneous catalysts permits combustion at lower temperatures compared with thermal combustion. Herein, we developed new catalysts of palladium-supported halloysite nanotubes (HNTs) for methane combustion. This was performed via chemical modification of HNTs using four different species i.e. H2SO4 (HNTs-H2SO4), NaOH (HNTs-NaOH), sodium dodecyl sulfate (HNTs-SDS), and cetyltrimethylammonium bromide (HNTs-CTAB). After chemical modification, Pd was deposited on the pretreated HNTs and the impact of chemical treatment on the morphology, crystal structure, textural properties, and methane oxidation activity was studied. All catalysts based on chemically modified HNTs exhibited enhanced catalytic performance towards methane combustion compared to Pd-supported on pristine HNTs, in particular, Pd/alkali-treated HNTs (Pd/HNTs-NaOH) revealed the highest catalytic activity towards methane combustion with the temperature of complete conversion (T100) equals 385 °C and activation energy of 79.15 kJ mol−1. Furthermore, the same sample displayed enhanced stability compared to other counterparts. This was assigned to the confinement of Pd nanoparticles at the inner surface which enhances the catalyst-support interaction, increases the number of surface active sites, and enhances the resistance to sintering at high temperatures.
Yahia H. Ahmad; Assem T. Mohamed; Siham Y. Al-Qaradawi. Exploring halloysite nanotubes as catalyst support for methane combustion: Influence of support pretreatment. Applied Clay Science 2021, 201, 105956 .
AMA StyleYahia H. Ahmad, Assem T. Mohamed, Siham Y. Al-Qaradawi. Exploring halloysite nanotubes as catalyst support for methane combustion: Influence of support pretreatment. Applied Clay Science. 2021; 201 ():105956.
Chicago/Turabian StyleYahia H. Ahmad; Assem T. Mohamed; Siham Y. Al-Qaradawi. 2021. "Exploring halloysite nanotubes as catalyst support for methane combustion: Influence of support pretreatment." Applied Clay Science 201, no. : 105956.
Development of self-assembled nanoarchitectures of tailored morphology and composition for diversified applications have received great interest in the last decades. Pt-based nanocrystals (NCs) exhibited enhanced catalytic performance towards different applications specially as electrocatalysts for fuel cells. Herein, ternary PtIrCu nanocrystals (NCs) were prepared via one-pot synthesis procedure and employed as electrocatalyst for methanol oxidation reaction (MOR) in acid medium. The as-prepared ternary NCs exhibited mass activity of 863 mA mg−1 which is almost 1.5, 2.2, and 6.0 times more greater than that of PtCu, PtIr, and Pt/C, respectively. Additionally, after stability test for 1000 s, the retained current density on PtIrCu NCs was 13.6 times higher than that on Pt/C. The enhanced catalytic activity and durability of ternary PtIrCu NCs compared to PtCu, PtIr, and Pt/C was assigned to the strain and electronic effects which enhance the oxidation kinetics and enhance the poisoning tolerance towards CO-like intermediate species.
Yahia H. Ahmad; Hany A. El-Sayed; Assem T. Mohamed; Amina S. Aljaber; Siham Y. Al-Qaradawi. Rational one-pot synthesis of ternary PtIrCu nanocrystals as robust electrocatalyst for methanol oxidation reaction. Applied Surface Science 2020, 534, 147617 .
AMA StyleYahia H. Ahmad, Hany A. El-Sayed, Assem T. Mohamed, Amina S. Aljaber, Siham Y. Al-Qaradawi. Rational one-pot synthesis of ternary PtIrCu nanocrystals as robust electrocatalyst for methanol oxidation reaction. Applied Surface Science. 2020; 534 ():147617.
Chicago/Turabian StyleYahia H. Ahmad; Hany A. El-Sayed; Assem T. Mohamed; Amina S. Aljaber; Siham Y. Al-Qaradawi. 2020. "Rational one-pot synthesis of ternary PtIrCu nanocrystals as robust electrocatalyst for methanol oxidation reaction." Applied Surface Science 534, no. : 147617.
Direct glucose fuel cells (DGFCs) received great interest due to non-toxicity, low cost, and renewability. Herein, we demonstrated the synthesis of novel porous AuPtPd nanocrystals (NCs) via plausible one-pot synthesis route. This was implemented by reduction of the metal precursors with l-ascorbic acid in the presence of polyvinylpyrrolidone (PVP) as a structure-directing agent. TEM (transmission electron microscopy) images of the as-synthesized nanocrystals depicted porous nanodendritic morphology with particle size ranging from 20 to 30 nm. The catalytic performance of AuPtPd NCs was investigated towards glucose oxidation reaction (GOR) in alkaline medium compared to AuPt, PtPd, and Pt/C. The delivered maximum oxidation current density over AuPtPd was 10.1 mA cm−2, which is nearly 1.4, 1.8, and 3.5 times greater than AuPt, PtPd, and Pt/C, respectively. Additionally, the ternary electrocatalyst exhibited higher electrochemical stability compared to binary alloys and Pt/C counterparts. Furthermore, AuPtPd revealed lower Tafel slope for GOR compared to binary alloys and Pt/C which affirm enhanced GOR kinetics. The outstanding catalytic performance of AuPtPd NCs was attributed to the synergistic effect of the alloying elements and the high anti-poisoning effect of Au and Pd metals which facilitates the adsorption of surface hydroxyls (OH)ads on the catalyst active sites and enhances the oxidation kinetics.
Yahia H. Ahmad; Assem T. Mohamed; Ahmed El-Shafei; Siham Y. Al-Qaradawi; Amina S. Aljaber. Facile one-step synthesis of supportless porous AuPtPd nanocrystals as high performance electrocatalyst for glucose oxidation reaction. International Journal of Hydrogen Energy 2020, 45, 19163 -19173.
AMA StyleYahia H. Ahmad, Assem T. Mohamed, Ahmed El-Shafei, Siham Y. Al-Qaradawi, Amina S. Aljaber. Facile one-step synthesis of supportless porous AuPtPd nanocrystals as high performance electrocatalyst for glucose oxidation reaction. International Journal of Hydrogen Energy. 2020; 45 (38):19163-19173.
Chicago/Turabian StyleYahia H. Ahmad; Assem T. Mohamed; Ahmed El-Shafei; Siham Y. Al-Qaradawi; Amina S. Aljaber. 2020. "Facile one-step synthesis of supportless porous AuPtPd nanocrystals as high performance electrocatalyst for glucose oxidation reaction." International Journal of Hydrogen Energy 45, no. 38: 19163-19173.
Direct ethanol fuel cells (DEFCs) have received great interest owing to their high power density and environmental friendness. Nevertheless, the designing of active, durable, and efficient anode for DEFCs is a profound challenge. In this context, we reported the synthesis of PtPd porous nanoclusters (PtPd PNCs) as electrocatalyst for ethanol oxidation reaction (EOR). This was implemented through two-step synthesis. Firstly, ternary AgPtPd nanodendrites (NDs) were synthesized via ultrasound-assisted co-reduction of the metal precursors using ascorbic acid (AA) as a mild reductant and Pluronic F127 as structure-directing agent. Thereafter, PtPd PNCs were created by selective chemical etching of AgPtPd nanocrystals in 1 M HNO3. The textural properties, morphology, and elemental composition of the studied electrocatalysts were investigated, and their catalytic activities towards ethanol electrooxidation were examined. PtPd PNCs revealed a high surface area of 83.0 m2 g−1 and high porosity compared to its counterparts. Additionally, it depicted enhanced catalytic performance towards ethanol electrooxidation in 1 M KOH with mass activity of 1.8 A mg−1 compared to PtPd NDs (0.97 A mg−1), Pt NDs (0.51 A mg−1), and Pt/C (0.33 A mg−1). The enhanced catalytic performance of PtPd PNCs was ascribed to high surface area, high porosity, and increased active sites.
Yahia H. Ahmad; Assem T. Mohamed; Abdullah Alashraf; Maha Matalqeh; Ahmed El-Shafei; Siham Y. Al-Qaradawi; Amina S. Aljaber. Highly porous PtPd nanoclusters synthesized via selective chemical etching as efficient catalyst for ethanol electro-oxidation. Applied Surface Science 2019, 508, 145222 .
AMA StyleYahia H. Ahmad, Assem T. Mohamed, Abdullah Alashraf, Maha Matalqeh, Ahmed El-Shafei, Siham Y. Al-Qaradawi, Amina S. Aljaber. Highly porous PtPd nanoclusters synthesized via selective chemical etching as efficient catalyst for ethanol electro-oxidation. Applied Surface Science. 2019; 508 ():145222.
Chicago/Turabian StyleYahia H. Ahmad; Assem T. Mohamed; Abdullah Alashraf; Maha Matalqeh; Ahmed El-Shafei; Siham Y. Al-Qaradawi; Amina S. Aljaber. 2019. "Highly porous PtPd nanoclusters synthesized via selective chemical etching as efficient catalyst for ethanol electro-oxidation." Applied Surface Science 508, no. : 145222.
Yahia H. Ahmad; Assem T. Mohamed; Walid M.I. Hassan; Ahmed Soliman; Khaled A. Mahmoud; Amina S. Aljaber; Siham Y. Al-Qaradawi. Bimetallic palladium-supported halloysite nanotubes for low temperature CO oxidation: Experimental and DFT insights. Applied Surface Science 2019, 493, 70 -80.
AMA StyleYahia H. Ahmad, Assem T. Mohamed, Walid M.I. Hassan, Ahmed Soliman, Khaled A. Mahmoud, Amina S. Aljaber, Siham Y. Al-Qaradawi. Bimetallic palladium-supported halloysite nanotubes for low temperature CO oxidation: Experimental and DFT insights. Applied Surface Science. 2019; 493 ():70-80.
Chicago/Turabian StyleYahia H. Ahmad; Assem T. Mohamed; Walid M.I. Hassan; Ahmed Soliman; Khaled A. Mahmoud; Amina S. Aljaber; Siham Y. Al-Qaradawi. 2019. "Bimetallic palladium-supported halloysite nanotubes for low temperature CO oxidation: Experimental and DFT insights." Applied Surface Science 493, no. : 70-80.
Luping Lyu; Rui Su; Siham Y. Al-Qaradawi; Khalid Al-Saad; Ahmed El-Shafei. Corrigendum to “Three-component one-pot reaction for molecular engineering of novel cost-effective highly rigid quinoxaline-based photosensitizers for highly efficient DSSCs application: Remarkable photovoltage”[Dyes and Pigments 171(2019) 107683–107690]. Dyes and Pigments 2019, 173, 107962 .
AMA StyleLuping Lyu, Rui Su, Siham Y. Al-Qaradawi, Khalid Al-Saad, Ahmed El-Shafei. Corrigendum to “Three-component one-pot reaction for molecular engineering of novel cost-effective highly rigid quinoxaline-based photosensitizers for highly efficient DSSCs application: Remarkable photovoltage”[Dyes and Pigments 171(2019) 107683–107690]. Dyes and Pigments. 2019; 173 ():107962.
Chicago/Turabian StyleLuping Lyu; Rui Su; Siham Y. Al-Qaradawi; Khalid Al-Saad; Ahmed El-Shafei. 2019. "Corrigendum to “Three-component one-pot reaction for molecular engineering of novel cost-effective highly rigid quinoxaline-based photosensitizers for highly efficient DSSCs application: Remarkable photovoltage”[Dyes and Pigments 171(2019) 107683–107690]." Dyes and Pigments 173, no. : 107962.
Bimetallic Pd-supported halloysite nanotubes revealed outstanding catalytic activity towards catalytic methane oxidation especially PdNi.
Yahia H. Ahmad; Assem T. Mohamed; Khaled A. Mahmoud; Amina S. Aljaber; Siham Y. Al-Qaradawi. Natural clay-supported palladium catalysts for methane oxidation reaction: effect of alloying. RSC Advances 2019, 9, 32928 -32935.
AMA StyleYahia H. Ahmad, Assem T. Mohamed, Khaled A. Mahmoud, Amina S. Aljaber, Siham Y. Al-Qaradawi. Natural clay-supported palladium catalysts for methane oxidation reaction: effect of alloying. RSC Advances. 2019; 9 (56):32928-32935.
Chicago/Turabian StyleYahia H. Ahmad; Assem T. Mohamed; Khaled A. Mahmoud; Amina S. Aljaber; Siham Y. Al-Qaradawi. 2019. "Natural clay-supported palladium catalysts for methane oxidation reaction: effect of alloying." RSC Advances 9, no. 56: 32928-32935.
Saba Ashraf; Rui Su; Javeed Akhtar; Humaira M. Siddiqi; Ahmed Shuja; Khalid A. Al-Saad; Siham Y. Al-Qaradawi; Ahmed El-Shafei. Corrigendum to “Investigations into structure-property relationships of novel Ru(II) dyes with N,N′-Diethyl group in ancillary ligand for dye-sensitized solar cells” [Dyes Pigments 171(2019) 107754–107762]. Dyes and Pigments 2019, 173, 107955 .
AMA StyleSaba Ashraf, Rui Su, Javeed Akhtar, Humaira M. Siddiqi, Ahmed Shuja, Khalid A. Al-Saad, Siham Y. Al-Qaradawi, Ahmed El-Shafei. Corrigendum to “Investigations into structure-property relationships of novel Ru(II) dyes with N,N′-Diethyl group in ancillary ligand for dye-sensitized solar cells” [Dyes Pigments 171(2019) 107754–107762]. Dyes and Pigments. 2019; 173 ():107955.
Chicago/Turabian StyleSaba Ashraf; Rui Su; Javeed Akhtar; Humaira M. Siddiqi; Ahmed Shuja; Khalid A. Al-Saad; Siham Y. Al-Qaradawi; Ahmed El-Shafei. 2019. "Corrigendum to “Investigations into structure-property relationships of novel Ru(II) dyes with N,N′-Diethyl group in ancillary ligand for dye-sensitized solar cells” [Dyes Pigments 171(2019) 107754–107762]." Dyes and Pigments 173, no. : 107955.
LiNi0.5Mn1.5O4 (LNMO) is one of the most promising cathode materials for next-generation lithium-ion batteries for rapid charging-discharge applications. The surfaces of LNMO samples are coated with different amounts (0.5-2.0 wt. %) of silica (SiO2) using a cost-effective and scalable ball milling process, and the surface-modified samples showing excellent electrochemical stability with conventional liquid electrolyte. The advantage of this coating is clearly demonstrated by the improved electrochemical performance at ambient and elevated temperatures (25 °C and 55 °C) using half- and full-cell configurations. The solid electrolyte interface (SEI) and coating properties have been highlighted by Ex situ TEM analysis, which indicates the close attachment and good wetting of the SiO2 layer with the LNMO active particles. Importantly, the 1 wt. % SiO2-coated material cycled at 10 C, 40 C and 80 C rates for 400 cycles and excellent cycling stability with capacity retentions of 96.7, 87.9 and 82.4 %, respectively. The 1 wt. % SiO2-coated material also shows excellent cycling stability when charged at 6C (10 min.) and discharged at C/3 for 500 cycles. The interfacial resistances of the SiO2-coated LiNi0.5Mn1.5O4 is found to be much lower compared to bare material and does not considerably increase with the amount of coating. Overall, the scalable and cost-effective strategy of SiO2 coating applied to LiNi0.5Mn1.5O4 lowers the interfacial charge transfer resistance and enables the materials to be suitable for extremely fast-charging electric vehicle battery applications.
Umair Nisar; Sara Ahmad J. A. Al-Hail; Ramesh Kumar Petla; Rana A Shakoor; Rachid Essehli; Ramazan Kahraman; Siham Y. AlQaradawi; Do Kyung Kim; Ilias Belharouak; Ruhul Amin. Understanding the Origin of the Ultrahigh Rate Performance of a SiO2-Modified LiNi0.5Mn1.5O4 Cathode for Lithium-Ion Batteries. ACS Applied Energy Materials 2019, 2, 7263 -7271.
AMA StyleUmair Nisar, Sara Ahmad J. A. Al-Hail, Ramesh Kumar Petla, Rana A Shakoor, Rachid Essehli, Ramazan Kahraman, Siham Y. AlQaradawi, Do Kyung Kim, Ilias Belharouak, Ruhul Amin. Understanding the Origin of the Ultrahigh Rate Performance of a SiO2-Modified LiNi0.5Mn1.5O4 Cathode for Lithium-Ion Batteries. ACS Applied Energy Materials. 2019; 2 (10):7263-7271.
Chicago/Turabian StyleUmair Nisar; Sara Ahmad J. A. Al-Hail; Ramesh Kumar Petla; Rana A Shakoor; Rachid Essehli; Ramazan Kahraman; Siham Y. AlQaradawi; Do Kyung Kim; Ilias Belharouak; Ruhul Amin. 2019. "Understanding the Origin of the Ultrahigh Rate Performance of a SiO2-Modified LiNi0.5Mn1.5O4 Cathode for Lithium-Ion Batteries." ACS Applied Energy Materials 2, no. 10: 7263-7271.
The spectrophotometric characteristics of the solid charge-transfer molecular complexes (CT) formed in the reaction of the electron donor 2-amino-6-methylpyridine (2A6MPy) with the π-acceptors tetracyanoethylene (TCNE), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 2,4,4,6-tetrabromo-2,5-cyclohexadienone (TBCHD) have been studied in chloroform at 25 °C. These were investigated through electronic and infrared spectra as well as elemental analysis. The results show that the formed solid CT-complexes have the formulas [(2A6MPy)(TCNE)2], [(2A6MPy)2(DDQ)], [(2A6MPy)4(TBCHD)] in full agreement with the known reaction stoichiometries in solution as well as the elemental measurements. The formation constant kCT, molar extinction coefficient εCT, free energy change ΔG0 and CT energy ECT have been calculated for the CT-complexes [(2A6MPy)(TCNE) 2] and [(2A6MPy)2(DDQ)].
Sherzod Madrahimov; Adel Mostafa; Veeranna Yempally; Joelle Fadlallah; Siham Y. AlQaradawi. Electronic, infrared, mass spectrometry and thermal studies on the reaction of 2-amino-6-methylpyridine with π-acceptors. Journal of Molecular Structure 2019, 1199, 127021 .
AMA StyleSherzod Madrahimov, Adel Mostafa, Veeranna Yempally, Joelle Fadlallah, Siham Y. AlQaradawi. Electronic, infrared, mass spectrometry and thermal studies on the reaction of 2-amino-6-methylpyridine with π-acceptors. Journal of Molecular Structure. 2019; 1199 ():127021.
Chicago/Turabian StyleSherzod Madrahimov; Adel Mostafa; Veeranna Yempally; Joelle Fadlallah; Siham Y. AlQaradawi. 2019. "Electronic, infrared, mass spectrometry and thermal studies on the reaction of 2-amino-6-methylpyridine with π-acceptors." Journal of Molecular Structure 1199, no. : 127021.
Structure-property relationships of four novel bipyridyl Ru(II) complexes, denoted as SD-22, SD-24, SD-26 and SD-28, are reported herein. The molecular structures of all four photosensitizers were confirmed using FT-IR, 1H NMR and mass spectrometry. Photovoltaic characteristics of the photosensitizers were evaluated under 1.5 a.m. standard illumination condition, in presence of deoxycholic acid as co-adsorbent, and subsequently compared to the performance of the benchmark, Z907. SD-22 showed an IPCE of 52% and 50% at 440 nm and 550 nm, respectively, a short-circuit photocurrent density (JSC) of 17.37 mA cm−2, open-circuit photovoltage (VOC) of 0.63 V and fill factor (FF) of 0.66, producing an overall conversion efficiency (η) of 7.31%, which outperformed Z907 (7.02%) under the same experimental device conditions. The η of the other photosensitizers is in the following order: SD-22 > SD-28 > SD-26 > SD-24. Photosensitizer SD-22 has N,N′-dialkyl group attached to a benzene ring while SD-24 has N,N′-dialkyl without a benzene ring. The extended conjugation in SD-22 translated into higher overall solar-to-electric conversion efficiency. Substitution of dialkylamino-based ancillary ligands of Ru(II) dyes SD-26 and SD-28 with –OCH3 and –OC6H13 also demonstrated that the photovoltaic performance of polypyridyl ruthenium photosensitizers is a function of the donating power of ancillary ligands as well as the steric effect of alkoxy auxochromes at –ortho position.
Saba Ashraf; Rui Su; Javeed Akhtar; Humaira M. Siddiqi; Ahmed Shuja; Khalid A. Al-Saad; Siham Y. Al-Qaradawi; Ahmed El-Shafei. Investigations into structure-property relationships of novel Ru(II) dyes with N,N′-Diethyl group in ancillary ligand for dye-sensitized solar cells. Dyes and Pigments 2019, 171, 107754 .
AMA StyleSaba Ashraf, Rui Su, Javeed Akhtar, Humaira M. Siddiqi, Ahmed Shuja, Khalid A. Al-Saad, Siham Y. Al-Qaradawi, Ahmed El-Shafei. Investigations into structure-property relationships of novel Ru(II) dyes with N,N′-Diethyl group in ancillary ligand for dye-sensitized solar cells. Dyes and Pigments. 2019; 171 ():107754.
Chicago/Turabian StyleSaba Ashraf; Rui Su; Javeed Akhtar; Humaira M. Siddiqi; Ahmed Shuja; Khalid A. Al-Saad; Siham Y. Al-Qaradawi; Ahmed El-Shafei. 2019. "Investigations into structure-property relationships of novel Ru(II) dyes with N,N′-Diethyl group in ancillary ligand for dye-sensitized solar cells." Dyes and Pigments 171, no. : 107754.
Rational design of graphitic carbon nitride nanostructures (gC3N4) is vital in various catalytic applications. Herein, we synthesized porous gC3N4 nanotubes (gC3N4NTs) doped with Pd and Cu (Pd/Cu/gC3N4NTs) via the consecutive polymerization of melamine in an ethylene glycol solution containing the metal precursors followed by annealing. The gC3N4NTs, thus produced, possess a well-defined one-dimensional porous nanotube architecture, large surface area (240 m2 g−1), and a homogenous dispersion of Pd and Cu without the need for templates and/or multistep reactions. This merits the CO oxidation activity of Pd/Cu/gC3N4NTs by 56 °C and 96 °C higher than that of Pd/gC3N4NTs and Cu/gC3N4NTs, respectively. The CO2 reduction activity of Pd/Cu/gC3N4NTs was 5.5-fold higher than metal-free gC3N4NTs. Also, the UV-light irradiation enhanced the CO2 performance of Pd/Cu/gC3N4NTs by three times. The presented study may pave the way for the utilization of metal-doped gC3N4NTs for various applications.
Kamel Eid; Mostafa H. Sliem; Khouloud Jlassi; Amal S. Eldesoky; Ghada G. Abdo; Siham Y. Al-Qaradawi; Mohammed A. Sharaf; Aboubakr M. Abdullah; Ahmed A. Elzatahry. Precise fabrication of porous one-dimensional gC3N4 nanotubes doped with Pd and Cu atoms for efficient CO oxidation and CO2 reduction. Inorganic Chemistry Communications 2019, 107, 107460 .
AMA StyleKamel Eid, Mostafa H. Sliem, Khouloud Jlassi, Amal S. Eldesoky, Ghada G. Abdo, Siham Y. Al-Qaradawi, Mohammed A. Sharaf, Aboubakr M. Abdullah, Ahmed A. Elzatahry. Precise fabrication of porous one-dimensional gC3N4 nanotubes doped with Pd and Cu atoms for efficient CO oxidation and CO2 reduction. Inorganic Chemistry Communications. 2019; 107 ():107460.
Chicago/Turabian StyleKamel Eid; Mostafa H. Sliem; Khouloud Jlassi; Amal S. Eldesoky; Ghada G. Abdo; Siham Y. Al-Qaradawi; Mohammed A. Sharaf; Aboubakr M. Abdullah; Ahmed A. Elzatahry. 2019. "Precise fabrication of porous one-dimensional gC3N4 nanotubes doped with Pd and Cu atoms for efficient CO oxidation and CO2 reduction." Inorganic Chemistry Communications 107, no. : 107460.
A simple three-component one-pot approach was developed to generate three novel highly rigid quinoxaline-based dyes, which were further investigated as sensitizers of dye-sensitized solar cells (DSSCs). The effect of different push-pull molecular motifs containing various donors and attachment of long alkyl chains on photophysical, electrochemical and photovoltaic performances, along with theoretical calculations were studied comprehensively. In particular, LY03-based DSSCs showed the highest efficiency of 7.04% with a short-circuit photocurrent density (JSC) of 14.32 mA cm−2, an open-circuit photovoltage (VOC) of 910 mV and a fill factor (FF) of 0.54% under AM 1.5 irradiation (100 mW cm−2). The results confirm that improving the molecular rigidity of sensitizer and incorporation of long alkyl chains into an auxiliary acceptor and donor is one of the most effective pathways to prevent “trade-off” effect, which translated into remarkable improvement in open-circuit photovoltage of 0.91 V, hence, enhancing the photovoltaic performance.
Luping Lyu; Rui Su; Siham Y. Al-Qaradawi; Khalid A. Al-Saad; Ahmed El-Shafei. Three-component one-pot reaction for molecular engineering of novel cost-effective highly rigid quinoxaline-based photosensitizers for highly efficient DSSCs application: Remarkable photovoltage. Dyes and Pigments 2019, 171, 107683 .
AMA StyleLuping Lyu, Rui Su, Siham Y. Al-Qaradawi, Khalid A. Al-Saad, Ahmed El-Shafei. Three-component one-pot reaction for molecular engineering of novel cost-effective highly rigid quinoxaline-based photosensitizers for highly efficient DSSCs application: Remarkable photovoltage. Dyes and Pigments. 2019; 171 ():107683.
Chicago/Turabian StyleLuping Lyu; Rui Su; Siham Y. Al-Qaradawi; Khalid A. Al-Saad; Ahmed El-Shafei. 2019. "Three-component one-pot reaction for molecular engineering of novel cost-effective highly rigid quinoxaline-based photosensitizers for highly efficient DSSCs application: Remarkable photovoltage." Dyes and Pigments 171, no. : 107683.
The solid charge-transfer (CT) molecular complexes formed in the reaction of the electron donor 1,4,8,11-tetraazacyclotetradecane (TACTD) with the π-electron acceptors 2,4,6-tetrafluoro-1,4-benzoquinone (TFQ), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 2,4,4,6-tetrabromo-2,5-cyclohexadienone (TBCHD) have been investigated spectrophotometrically in chloroform at 25 °C. These were characterized through electronic and infrared spectra as well as elemental and thermal analysis. The obtained results showed that the formed solid CT-complexes have the formulas [(TACTD)(TFQ)2] and [(TACTD)(DDQ)2] and [(TACTD)(TBCHD)2] in full agreement with the known reaction stoichiometry in solution as well as the elemental measurements. The formation constant kCT, molar extinction coefficient εCT, free energy change ΔG0, CT energy ECT and the ionization potential Ip have been calculated for these CT-complexes.
Adel Mostafa; Sherzod Madrahimov; Joelle Fadlallah; Siham Y. AlQaradawi. UV–Vis, IR spectra, mass spectrometry and thermal studies of charge transfer complexes formed in the reaction of 1, 4, 8, 11-tetraazacyclotetradecane with π-electron acceptors. Journal of Molecular Liquids 2019, 284, 616 -624.
AMA StyleAdel Mostafa, Sherzod Madrahimov, Joelle Fadlallah, Siham Y. AlQaradawi. UV–Vis, IR spectra, mass spectrometry and thermal studies of charge transfer complexes formed in the reaction of 1, 4, 8, 11-tetraazacyclotetradecane with π-electron acceptors. Journal of Molecular Liquids. 2019; 284 ():616-624.
Chicago/Turabian StyleAdel Mostafa; Sherzod Madrahimov; Joelle Fadlallah; Siham Y. AlQaradawi. 2019. "UV–Vis, IR spectra, mass spectrometry and thermal studies of charge transfer complexes formed in the reaction of 1, 4, 8, 11-tetraazacyclotetradecane with π-electron acceptors." Journal of Molecular Liquids 284, no. : 616-624.
The development of highly efficient and durable anode materials for ethanol electro-oxidation remains a challenge. Herein, we report the synthesis of Pt1−x−yIrxNiy nanocrystals via one-step procedure by ultrasonic-assisted co-reduction of the metal precursors using ascorbic acid as a mild reducing agent and pluronic F127 as a structure directing agent. The catalytic performance of this ternary catalyst towards electrochemical oxidation of ethanol was examined and compared to its mono and binary Pt counterparts (Pt, Pt1−xIrx, and Pt1−yNiy) that are synthesized by the same method. TEM analysis showed a porous nanodendritic structure for the synthesized ternary electrocatalyst with an average size of 20 ± 1 nm. The electrochemical measurements revealed an electrochemically active surface area, ECSA, of 73 m2 g−1. The as-synthesized ternary electrocatalyst showed an improved catalytic activity towards ethanol oxidation in 1 M KOH with a measured mass activity of 3.8 A mg−1 which is 1.7, 2.0, and 3.2 times higher than that of Pt1−xIrx, Pt1−yNiy, and Pt, respectively. Additionally, the Pt1−x−yIrxNiy nanocrystals expressed high poisoning tolerance (jf/jb = 4.5) and high durability compared to its mono and binary counterparts.
Yahia H. Ahmad; Assem T. Mohamed; Khaled Youssef; Subhajit Kundu; K. Andre Mkhoyan; Siham Y. Al-Qaradawi. Rational synthesis of ternary PtIrNi nanocrystals with enhanced poisoning tolerance for electrochemical ethanol oxidation. Electrochemistry Communications 2019, 101, 61 -67.
AMA StyleYahia H. Ahmad, Assem T. Mohamed, Khaled Youssef, Subhajit Kundu, K. Andre Mkhoyan, Siham Y. Al-Qaradawi. Rational synthesis of ternary PtIrNi nanocrystals with enhanced poisoning tolerance for electrochemical ethanol oxidation. Electrochemistry Communications. 2019; 101 ():61-67.
Chicago/Turabian StyleYahia H. Ahmad; Assem T. Mohamed; Khaled Youssef; Subhajit Kundu; K. Andre Mkhoyan; Siham Y. Al-Qaradawi. 2019. "Rational synthesis of ternary PtIrNi nanocrystals with enhanced poisoning tolerance for electrochemical ethanol oxidation." Electrochemistry Communications 101, no. : 61-67.
The poor wettability and high cost of the carbonaceous electrodes materials prohibited the practical applications of microbial fuel cells (MFCs) on large scale. Here, a novel nanoparticles of metal sheathed with metal oxide is electrodeposited on carbon paper (CP) to introduce as high-performance anodes of microbial fuel cell (MFC). This thin layer of metal/metal oxide significantly enhance the microbial adhesion, the wettability of the anode surface and decrease the electron transfer resistance. The investigation of the modified CP anodes in an air-cathode MFCs fed by various biocatalyst cultures shows a significant improving in the MFC performance. Where, the generated power and current density was 140% and 210% higher as compared to the pristine CP. Mixed culture of exoelectrogenic microorganism in wastewater exhibited good performance and generated higher power and current density compared to yeast as pure culture. The excellent capacitance with a distinctive nanostructure morphology of the modified-CP open an avenues for practical applications of MFCs.
Hend Omar Mohamed; Enas Taha Sayed; M. Obaid; Yun-Jeong Choi; Sung-Gwan Park; Siham Al-Qaradawi; Kyu-Jung Chae. Transition metal nanoparticles doped carbon paper as a cost-effective anode in a microbial fuel cell powered by pure and mixed biocatalyst cultures. International Journal of Hydrogen Energy 2018, 43, 21560 -21571.
AMA StyleHend Omar Mohamed, Enas Taha Sayed, M. Obaid, Yun-Jeong Choi, Sung-Gwan Park, Siham Al-Qaradawi, Kyu-Jung Chae. Transition metal nanoparticles doped carbon paper as a cost-effective anode in a microbial fuel cell powered by pure and mixed biocatalyst cultures. International Journal of Hydrogen Energy. 2018; 43 (46):21560-21571.
Chicago/Turabian StyleHend Omar Mohamed; Enas Taha Sayed; M. Obaid; Yun-Jeong Choi; Sung-Gwan Park; Siham Al-Qaradawi; Kyu-Jung Chae. 2018. "Transition metal nanoparticles doped carbon paper as a cost-effective anode in a microbial fuel cell powered by pure and mixed biocatalyst cultures." International Journal of Hydrogen Energy 43, no. 46: 21560-21571.
Clinopyroxene LiVSi2O6 phase has been synthesised in this study by a single step solid state reaction in argon atmosphere at 900 °C, and its electrochemical properties have been investigated. Graphene composite of the material has also been prepared by assimilating GO (graphene oxide) to the reactants which gets reduced in situ to rGO (reduced graphene oxide) during the annealing process. Structure and morphology of the samples have been characterised by powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and surface area (BET) measurements. Lithium storage properties of the material were examined using galvanostatic cycling, cyclic voltammetry and electrochemical impedance spectroscopy studies. The rGO composite shows better capacity retention than the pristine sample, and an initial discharge capacity of 110 mAh g−1 was obtained for the rGO composite.
A. Shahul Hameed; M. V. Reddy; Siham AlQaradawi; Stefan Adams. Synthesis, structural and lithium storage studies of graphene-LiVSi2O6 composites. Ionics 2018, 25, 1559 -1566.
AMA StyleA. Shahul Hameed, M. V. Reddy, Siham AlQaradawi, Stefan Adams. Synthesis, structural and lithium storage studies of graphene-LiVSi2O6 composites. Ionics. 2018; 25 (4):1559-1566.
Chicago/Turabian StyleA. Shahul Hameed; M. V. Reddy; Siham AlQaradawi; Stefan Adams. 2018. "Synthesis, structural and lithium storage studies of graphene-LiVSi2O6 composites." Ionics 25, no. 4: 1559-1566.