Samy El-Shall | |
---|---|
Born | Cairo, Egypt |
Nationality | Egyptian American |
Alma mater | Cairo University Georgetown University |
Awards | Virginia Outstanding Scientist, 2018 Jefferson Science Fellow, 2012 ACS-VA Distinguished Research Award, 2009 |
Scientific career | |
Fields | Cluster Ions, Vapor Phase Nucleation, Nanomaterials, Nanocatalysis, Astrochemistry |
Institutions | Virginia Commonwealth University |
Samy El-Shall (Mohamed Samy El-Shall) is an Egyptian-American physical chemist and a researcher in nanoscience, heterogeneous catalysis, molecular clusters and cluster ions, nucleation and ion mobility. He is the Mary Eugenia Kapp Endowed Chair in Chemistry and Commonwealth Professor at Virginia Commonwealth University (VCU). [1]
El-Shall was born in Cairo, Egypt, and spent his early life in Cairo. He is the grandson of Sheikh Mahmud Shaltut. He earned his B.S. degree in chemistry in 1976, and M.S. degree in physical chemistry in 1980 both from Cairo University. El-Shall earned his doctoral degree in physical chemistry from Georgetown University in 1985. [2]
El-Shall started his academic career in 1986 as a research associate at the University of California at Los Angeles (UCLA) while working with Howard Reiss on vapor phase nucleation and with Robert L. Whetten on molecular clusters and cluster ions. Since 1989, he has been on the faculty of the Chemistry Department, and has served as the Chair of the Chemistry Department at Virginia Commonwealth University (VCU) from 2015 to 2021. He is the Mary Eugenia Kapp Endowed Chair in Chemistry and Commonwealth Professor at Virginia Commonwealth University (VCU). [1]
El-Shall served as a Senior Science Advisor in the Bureau for the Middle East, Middle East Regional Cooperation (MERC) Program of the USAID. He focused on enhancing and expanding joint Arab-Israeli research activities through MERC projects, and has also conducted site project reviews in Israel, Jordan and Egypt to improve collaborative research opportunities across borders and enhance implementation of research results. He also worked on creating new initiatives for young investigators in order to catalyze the next generation of Arab-Israeli research cooperation, and to create long-term sustainable collaborations between Arab and Israeli scientists. [1]
El-Shall's research interests include nanostructured materials, graphene and nanocatalysis for energy and environmental applications, gas phase clusters and vapor phase nucleation. El-Shall is the architect of the concept of cluster polymerization, and intracluster polymerization was first demonstrated in his lab at VCU. [3] [4]
As of 2021, El-Shall has written over 290 publications in refereed journals in the areas of physical chemistry, catalysis and nanoscience. He also holds 11 US patents on the synthesis of nanomaterials, nanoparticle catalysts, graphene, graphene-supported catalysts and graphene-based materials for the removal of pollutants from water. [5]
El-Shall was the first to apply the Resonant Enhanced Multiphoton Ionization (REMPI) technique to selectively generate molecular ions within supersaturated host vapors and study the phenomena of ion-induced nucleation on well-defined ions. [6] [7] He also focused his study on the formation mechanisms of gold–zinc oxide hexagonal nanopyramids through heterogeneous nucleation using microwave synthesis. [8] In 2018, he demonstrated nucleation and growth process of gold nanoparticles initiated by nanosecond and femtosecond laser irradiation of aqueous solutions of [AuCl4]−. [9]
His group has also been involved in the development of a novel technique: Laser Vaporization Controlled Condensation (LVCC) for the synthesis of a variety of semiconductor, metal and metal oxide nanoparticles. [10] His research lab is currently focused on the applications of graphene in heterogeneous catalysis and energy conversion, and he developed novel microwave and laser methods for the synthesis of nanoparticle catalysts supported on graphene. [11] The recent discovery of efficient photo-thermal energy conversion by graphene-based materials by El-Shall's group has resulted in the development of new materials for efficient solar water desalination and the removal of heavy metals from contaminated water. [12]
Catalysis is the process of change in rate of a chemical reaction by adding a substance known as a catalyst. Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst.
Chemical vapor deposition (CVD) is a vacuum deposition method used to produce high-quality, and high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films.
A nanoparticle or ultrafine particle is usually defined as a particle of matter that is between 1 and 100 nanometres (nm) in diameter. The term is sometimes used for larger particles, up to 500 nm, or fibers and tubes that are less than 100 nm in only two directions. At the lowest range, metal particles smaller than 1 nm are usually called atom clusters instead.
Nanomaterial-based catalysts are usually heterogeneous catalysts broken up into metal nanoparticles in order to enhance the catalytic process. Metal nanoparticles have high surface area, which can increase catalytic activity. Nanoparticle catalysts can be easily separated and recycled. They are typically used under mild conditions to prevent decomposition of the nanoparticles.
Nanochemistry is an emerging sub-discipline of the chemical and material sciences that deals with the development of new methods for creating nanoscale materials. The term "nanochemistry" was first used by Ozin in 1992 as 'the uses of chemical synthesis to reproducibly afford nanomaterials from the atom "up", contrary to the nanoengineering and nanophysics approach that operates from the bulk "down"'. Nanochemistry focuses on solid-state chemistry that emphasizes synthesis of building blocks that are dependent on size, surface, shape, and defect properties, rather than the actual production of matter. Atomic and molecular properties mainly deal with the degrees of freedom of atoms in the periodic table. However, nanochemistry introduced other degrees of freedom that controls material's behaviors by transformation into solutions. Nanoscale objects exhibit novel material properties, largely as a consequence of their finite small size. Several chemical modifications on nanometer-scaled structures approve size dependent effects.
Nanofoams are a class of nanostructured, porous materials (foams) containing a significant population of pores with diameters less than 100 nm. Aerogels are one example of nanofoam.
Metal–organic frameworks (MOFs) are a class of compounds consisting of metal clusters coordinated to organic ligands to form one-, two-, or three-dimensional structures. The organic ligands included are sometimes referred to as "struts" or "linkers", one example being 1,4-benzenedicarboxylic acid (BDC).
As the world's energy demand continues to grow, the development of more efficient and sustainable technologies for generating and storing energy is becoming increasingly important. According to Dr. Wade Adams from Rice University, energy will be the most pressing problem facing humanity in the next 50 years and nanotechnology has potential to solve this issue. Nanotechnology, a relatively new field of science and engineering, has shown promise to have a significant impact on the energy industry. Nanotechnology is defined as any technology that contains particles with one dimension under 100 nanometers in length. For scale, a single virus particle is about 100 nanometers wide.
Janus particles are special types of nanoparticles or microparticles whose surfaces have two or more distinct physical properties. This unique surface of Janus particles allows two different types of chemistry to occur on the same particle. The simplest case of a Janus particle is achieved by dividing the particle into two distinct parts, each of them either made of a different material, or bearing different functional groups. For example, a Janus particle may have one-half of its surface composed of hydrophilic groups and the other half hydrophobic groups, the particles might have two surfaces of different color, fluorescence, or magnetic properties. This gives these particles unique properties related to their asymmetric structure and/or functionalization.
Magnetic nanoparticles are a class of nanoparticle that can be manipulated using magnetic fields. Such particles commonly consist of two components, a magnetic material, often iron, nickel and cobalt, and a chemical component that has functionality. While nanoparticles are smaller than 1 micrometer in diameter, the larger microbeads are 0.5–500 micrometer in diameter. Magnetic nanoparticle clusters that are composed of a number of individual magnetic nanoparticles are known as magnetic nanobeads with a diameter of 50–200 nanometers. Magnetic nanoparticle clusters are a basis for their further magnetic assembly into magnetic nanochains. The magnetic nanoparticles have been the focus of much research recently because they possess attractive properties which could see potential use in catalysis including nanomaterial-based catalysts, biomedicine and tissue specific targeting, magnetically tunable colloidal photonic crystals, microfluidics, magnetic resonance imaging, magnetic particle imaging, data storage, environmental remediation, nanofluids, optical filters, defect sensor, magnetic cooling and cation sensors.
Graphite oxide (GO), formerly called graphitic oxide or graphitic acid, is a compound of carbon, oxygen, and hydrogen in variable ratios, obtained by treating graphite with strong oxidizers and acids for resolving of extra metals. The maximally oxidized bulk product is a yellow solid with C:O ratio between 2.1 and 2.9, that retains the layer structure of graphite but with a much larger and irregular spacing.
An electrocatalyst is a catalyst that participates in electrochemical reactions. Electrocatalysts are a specific form of catalysts that function at electrode surfaces or, most commonly, may be the electrode surface itself. An electrocatalyst can be heterogeneous such as a platinized electrode. Homogeneous electrocatalysts, which are soluble, assist in transferring electrons between the electrode and reactants, and/or facilitate an intermediate chemical transformation described by an overall half reaction. Major challenges in electrocatalysts focus on fuel cells.
Silver nanoparticles are nanoparticles of silver of between 1 nm and 100 nm in size. While frequently described as being 'silver' some are composed of a large percentage of silver oxide due to their large ratio of surface to bulk silver atoms. Numerous shapes of nanoparticles can be constructed depending on the application at hand. Commonly used silver nanoparticles are spherical, but diamond, octagonal, and thin sheets are also common.
In chemistry, a catalyst support is the material, usually a solid with a high surface area, to which a catalyst is affixed. The activity of heterogeneous catalysts is mainly promoted by atoms present at the accessible surface of the material. Consequently, great effort is made to maximize the specific surface area of a catalyst. One popular method for increasing surface area involves distributing the catalyst over the surface of the support. The support may be inert or participate in the catalytic reactions. Typical supports include various kinds of activated carbon, alumina, and silica.
Carbon nanotube supported catalyst is a novel supported catalyst, using carbon nanotubes as the support instead of the conventional alumina or silicon support. The exceptional physical properties of carbon nanotubes (CNTs) such as large specific surface areas, excellent electron conductivity incorporated with the good chemical inertness, and relatively high oxidation stability makes it a promising support material for heterogeneous catalysis.
Nanoclusters are atomically precise, crystalline materials most often existing on the 0-2 nanometer scale. They are often considered kinetically stable intermediates that form during the synthesis of comparatively larger materials such as semiconductor and metallic nanocrystals. The majority of research conducted to study nanoclusters has focused on characterizing their crystal structures and understanding their role in the nucleation and growth mechanisms of larger materials. These nanoclusters can be composed either of a single or of multiple elements, and exhibit interesting electronic, optical, and chemical properties compared to their larger counterparts.
In materials and electric battery research, cobalt oxide nanoparticles usually refers to particles of cobalt(II,III) oxide Co
3O
4 of nanometer size, with various shapes and crystal structures.
Irshad Hussain is a Pakistani Scientist in the field of chemistry and among the few pioneers to initiate nanomaterials research in Pakistan.
Steven L. Suib is an American inorganic chemist, academic and researcher. He is a Board of Trustees Distinguished Professor of Chemistry at University of Connecticut. He is a director of the Institute of Materials Science and of the Center for Advanced Microscopy and Materials Analysis.
Ester Vázquez Fernández-Pacheco is an expert in carbon nanostructures and sustainable synthesis. She is a full professor at the University of Castilla la Mancha and a group leader at the MSOC Nanochemistry group.