Sarah A. Tolba
American University in Cairo
Charge carrierVisible spectrumTransition metalVacancy defectField electron emissionDielectricWettingNanomaterialsElectrospinningPhysical chemistryAdsorptionDensity functional theoryElectrochemical energy conversionNanoparticleHydrothermal circulationChemical physicsCatalysisHigh-? dielectricPhotocatalytic water splittingX-ray photoelectron spectroscopyMetal-organic frameworkBand gapChemistryEnergy level splittingDopantMaterials scienceDirect and indirect band gapsSurface energyHydrogen productionEnergy conversion efficiencyAnataseTitanium dioxideRutileOxideSurface chargeGrapheneWater splittingRaman spectroscopyChemical engineeringBimetallic stripPhase (matter)NanoindentationCarbonHydrogenPlatinumElectrochemistryCopperRedoxDopingAbsorption (electromagnetic radiation)PhotocatalysisPhotochemistryTitanium alloyNanofiberBinding energy
10Publications
5H-index
97Citations
Publications 10
Newest
#1Ahmed H. Biby (The: American University in Cairo)H-Index: 3
#2Sarah A. Tolba (The: American University in Cairo)H-Index: 5
Last. Nageh K. Allam (The: American University in Cairo)H-Index: 36
view all 3 authors...
Abstract The development of efficient photoelectrodes via defect engineering of wide-band gap metal oxides has been the prime focus for many years. Specifically, the effect of carbon defects in wide-band gap metal oxides on their performance in photoelectrochemical (PEC) applications raised numerous controversies and still elusive. Herein, the effect of various carbon defects in m-ZrO2 was investigated using the density functional theory to probe the thermodynamic, electronic, and optical proper...
1 CitationsSource
#1Mohamed F Sanad (UTEP: University of Texas at El Paso)H-Index: 7
#2Alain R. Puente Santiago (UTEP: University of Texas at El Paso)H-Index: 8
Last. Luis Echegoyen (UTEP: University of Texas at El Paso)H-Index: 87
view all 12 authors...
Platinum (Pt)-based-nanomaterials are currently the most successful catalysts for the oxygen reduction reaction (ORR) in electrochemical energy conversion devices such as fuel cells and metal-air batteries. Nonetheless, Pt catalysts have serious drawbacks, including low abundance in nature, sluggish kinetics, and very high costs, which limit their practical applications. Herein, we report the first rationally designed nonprecious Co-Cu bimetallic metal-organic framework (MOF) using a low-tempera...
1 CitationsSource
#1Sarah A. Tolba (The: American University in Cairo)H-Index: 5
#2Icell M. Sharafeldin (The: American University in Cairo)H-Index: 5
Last. Nageh K. Allam (The: American University in Cairo)H-Index: 36
view all 3 authors...
Abstract Doping is an effective way to engineer the electronic band structure of semiconductor materials and consequently their photocatalytic activity for hydrogen generation. In this work, periodic Density Functional Theory (DFT) was employed to compare the adsorption of H2S and H2O molecules on TiO2(101) anatase surfaces compared to four transition metal-doped TiO2(101) anatase surfaces; Cr4+-TiO2, V4+-TiO2, Mn4+-TiO2, and Nb4+-TiO2. The defect formation energy, molecular adsorption energy, h...
4 CitationsSource
#1Ahmed H. BibyH-Index: 3
#2Sarah A. TolbaH-Index: 5
Last. Nageh K. Allam (The: American University in Cairo)H-Index: 36
view all 3 authors...
The development of efficient photoelectrodes via defect engineering of wide-band gap metal oxides has been the prime focus for many years. Specifically, the effect of carbon defects in wide-band gap metal oxides on their performance in photoelectrochemical (PEC) applications raised numerous controversies and still elusive. Herein, the effect of various carbon defects in m-ZrO2 was investigated using the density functional theory to probe the thermodynamic, electronic, and optical properties of t...
1 Citations
#1Mahmoud A. Hamza (The: American University in Cairo)H-Index: 8
#2Ayat N. El-Shazly (The: American University in Cairo)H-Index: 9
Last. Nageh K. Allam (The: American University in Cairo)H-Index: 36
view all 4 authors...
Abstract Green and efficient energy technologies are a key point where nanoscience could make a difference in the paradigm shift from fossil fuels to renewable sources. One attractive possibility is the utilization of solar energy to obtain electricity or chemical fuel based on the ability of semiconductor nanomaterials to function as photocatalysts promoting various oxidation and reduction reactions under sunlight. We report on a novel class of Bi-based photocatalysts for hydrogen production vi...
15 CitationsSource
#1Alaa M. Soliman (The: American University in Cairo)H-Index: 2
#2Sarah A. Tolba (The: American University in Cairo)H-Index: 5
Last. Nageh K. Allam (The: American University in Cairo)H-Index: 36
view all 5 authors...
Abstract Stents used for cardiovascular applications are composed of three main elements; a metal, polymer coating and the specific drug component. Nickel-based metals and polymer coatings currently used in the stent market have increased the recurrence of in-stent restenosis and stent failure due to inflammation. In this study, a Ti-8Mn alloy was used to fabricate a nanostructured surface that can be used for drug eluting stents to overcome the hypersensitivity of metals that are currently used...
4 CitationsSource
#1Sarah A. Tolba (The: American University in Cairo)H-Index: 5
#2Nageh K. Allam (The: American University in Cairo)H-Index: 36
Monoclinic ZrO2 has recently emerged as a new highly efficient material for the photovoltaic and photocatalytic applications. Herein, first-principles calculations were carried out to understand how Hydrogen doping can affect the electronic structure and optical properties of the material. The effects of Hydrogen interstitial and substitutional doping at different sites and concentrations in m-ZrO2 were examined by an extensive model study to predict the best structure with the optimal propertie...
8 CitationsSource
#1Menna M. Hasan (The: American University in Cairo)H-Index: 3
#2Sarah A. Tolba (The: American University in Cairo)H-Index: 5
Last. Nageh K. Allam (The: American University in Cairo)H-Index: 36
view all 3 authors...
There is a growing need for new techniques to synthesize metallic copper nanoparticles due to their remarkable use in many advanced technologies. Herein, a novel method to synthesize stable and nonagglomerated zero-valent copper nanoparticles (ZVCNPs) via the in situ formation of reduced graphene oxide (rGO) during the electrospinning process in the presence of polyvinylpyrrolidone as a carbon source is presented. X-ray diffraction, Raman spectroscopy, electron paramagnetic resonance, transmissi...
13 CitationsSource
#1Sarah A. TolbaH-Index: 5
#2Kareem M. GameelH-Index: 4
Last. Nageh K. AllamH-Index: 36
view all 5 authors...
12 CitationsSource
#1Moamen M Soliman (The: American University in Cairo)H-Index: 2
#2Mohamed H Al Haron (The: American University in Cairo)H-Index: 1
Last. Nageh K. Allam (The: American University in Cairo)H-Index: 36
view all 8 authors...
Black TiO2 is being widely investigated due to its superior optical activity and potential applications in photocatalytic hydrogen generation. Herein, the limitations of the hydrogenation process of TiO2 nanostructures are unraveled by exploiting the fundamental tradeoffs affecting the overall efficiency of the water splitting process. To control the nature and concentration of defect states, different reduction rates are applied to sub-100 nm TiO2 nanotubes, chosen primarily for their superiori...
15 CitationsSource