Proposed Plan of Graduate Study. Ricardo Romo The project selected for my graduate study links local electric field maps, photocatalysis, and electron energy loss spectroscopy (EELS). The main goal of this project is to distinguish respective contributions of plasmonic heating and hot electron transfer in nanoantenna (NA)-transition metal dichalcogenides (TMD) heterostructures to decreasing the chemical reaction energy of sustainable Hydrogen (H2) photocatalysis. Enhancement in photocatalysis of hydrogen evolution reaction (HER) has been attributed to both plasmonic heating as well as to electron charge transfer effects. My research group recently showed that electrochemical reduction of NA directly to TMD edges enhances hot …show more content…
I will: (i) introduce modifications that account for hot electron transfer from nanoantenna to TMD; (ii) couple these calculations with simulation of HER photocatalysis; and (iii) use finite element analysis to determine local heating from plasmonic phonon dissipation. I will compare simulations with data from EELS, optical spectroscopy, infrared thermometry and voltammetry to distinguish effects of plasmonic heating and hot electron transfer on enhancement of H2 photocatalysis.
The physicochemically bonded NA will be characterize by using optical and scanning transmission electron spectroscopy (STEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy and Raman spectroscopy. This will improve understanding of photoinduced doping of TMDs by metal nanoantennae, which could benefit emerging catalytic applications. The bonding of the metal nanoantennae and the TMD together is a key determinant for transporting and accessing electrons, which can be characterized via EELS. This research will lay a foundation for future researchers to move forward with alternative energy through photocatalytic H2 dissociation and set the stage for my long-career goal of attaining a professorship with a keen interest of desalination energy. Metal NA can assist with the capture of thermal energy using the
Semiconductor Nano crystals or quantum dots are materials that are typically 2-20 nm in diameter, consisting of approximately twelve to fourteen thousand atoms. The effect of quantum confinement results, in the electrons and holes in the Nano crystal to exhibit quantized energy states; thus enabling them to exhibit novel physical properties that are not found in their bulk counterparts. Research in semiconductor quantum dots started with the realization that the optical and electronic properties of these particles were strongly dependent on particle size, due to quantum confinement of the charge carriers in small spaces.
In paper, Greene’s Jewelry has a strong case against Jennifer Lawson because Jennifer breached the confidentiality agreements that she signed with Greene’s Jewelry. In the agreement, it specifically indicated that Jennifer could never disclose any information regarding “Ever-Gold” creating process, which is patented and owned by Greene’s Jewelry. Jennifer not only stole a draft letter that contains the details of creating Ever-Gold but also took it to Greene’s competitor Howell Jewelry World in order to obtain a job offer from the company. The employment contract that Jennifer signed with Howell is a certain evidence of her unjust enrichment. Regarding Jennifer Lawson’s claim that she encountered wrongful termination at Greene’s, it is simply a misinterpretation of Greene’s legitimate reduction in force. The company no longer had a need for any junior executive secretaries. The downsizing was unfortunately but legal.
porphyrin-based compound, known commercially as verteporfin, also shows promise in the treatment of macular degeneration by selectively halting the growth of harmful blood vessels under the retina. The photochemical and optical properties of porphyrin compounds have also made them a target of research in the field of molecular electronics. One goal of this research has been to produce improved optoelectronic devices such as photovoltaic cells, OLEDs and OFETs by imitating the early steps of photosynthesis. 3 The high thermal and photostabilities of porphyrin compounds also contribute to their appeal in the field of material science. Supramolecular structures of porphyrin compounds have also been studied for their electrical properties, and have been used to build nanoarchitectures and molecular assemblies ranging in length from several nanometers to the millimeter scale.1 This particular project focuses on two metalloporphyrins: (Tetraphenylporphyrinato)zinc(II) (Zn(TPP)) and (Tetraphenylporphyrinato)copper(II) (Cu(TPP)). Energy transfer in systems consisting of zinc
In order to form metal hydrides, heat is released during the process which is exothermic reaction. The amount of heat released during the adsorption of hydrogen is the same as the amount of heat required to desorb the hydrogen. Therefore, as the stability of hydride formed getting higher, the heat needed to desorb hydrogen also higher. The energy needed to release the hydrogen from MgH2 is approximately 25% higher than the heating value of hydrogen. Although many efforts have been done on the Mg-based hydrides in recent years, it is still a challenge to find out an appropriate hydride of light metals (Zhou, 2004). The relatively high activation energy exists in the adsorption and desorption process leading the chemisorption process may become
It was found that copper hydrides show a very distinctive reactivity with their neutral oligomer structure.[#Jordan.2016] The copper hydride complexes can be used for catalytic processes as they make many organic reactions and transformations accessible.[#Jordan.2016] For example, copper hydrides can be used for the hydrosilylation and the hydrogenation of carbonyl compounds, to reduce unsaturated Alkynes to Alkenes, or even to reduce Alkenes themselves.[#Jordan.2016] Further, the reduction of CO_{2} and several other functional groups has been observed.[#Jordan.2016] Nanospheric polyhydrido copper cluster could further be used as a hydrogen storage which spontaneously releases H_{2} already upon irradiation with
This fear led so many scientists to figure out methods and ways to examine the cancer cells and cure it. In this report focuses on the most recent developments in the chemical synthesis of metal Nanorods, more specifically the gold Nanorods and silver nanorods, their properties and by extension some of their applications. It also studies into details a few nanotechniques and how they are applicable to various situations. One application is Cancer Cell Imaging and Photothermal
Pd-Ni/Al2O3 systems were investigated in the reaction of hydrogen oxidation in terms of their possible application as catalysts used in passive autocatalytic recombiners (PARs) used in nuclear power plants. Testing experiments, were carried out in a flowing system at different temperatures and humidity of the reaction mixture. The bimetallic catalysts exhibited higher response to the increase of temperature and higher resistance to inhibiting water than the monometallic palladium catalyst. They showed excellent stability during a few tens of hours, similarly, like their monometallic counterpart. Our bimetallic catalysts of hydrogen oxidation can be used as cheaper alternatives to catalysts based on the precious metals in the hydrogen oxidation without loss of their activity over time.
Layered two-dimensional (2D) transition metal dichalcogenides (TMDs) exhibit unique properties such as ease of energy band engineering by adjusting the number of layers or by Van der Waals heterostructures.1 Such salient features of TMDs make them promising for a wide range of electronic and optoelectronic applications.2-4 However, the transformation of basic science studies into viable device technologies necessitates large-area synthesis of device-quality TMDs. Significant research is ongoing to grow monolayer (ML) TMDs using chemical vapor deposition
Thin flakes of TMDs can be peeled off from bulk materials using adhesive tape, applied to the substrates and then identified by light interference using similar techniques used to develop graphene. Fig 6c shows a thin monolayer flake peeled off from the bulk material (Fig 6a) mechanically with the tape. Oxide nanosheets as well as other materials can be obtained using this method. Using the mechanical method of exfoliation helps to produce flakes of high purity that
Among the others metal NPs, the recent interest in the CuNPs is propelled by both, the advances of these NPs as a frugal alternatives for sumptuous metal NPs in the area of micro-electronics applications as well as the possibility of exploring them as ultimate antimicrobial agent.
The improvement is due to the reduction of the work function owing to the desorption of adsorbates by temperature increase or by ion-bombardment of the emitter surface. We have demonstrated the reduction of the work function of HfN thin films by two methods: heat treatment and ion bombardment.49 The initial work function of 4.73 eV was reduced to 4.0 eV by heat treatment at 300 °C. If this is also the case with FEAs, we can obtain substantially improved emission properties. One purpose of the study is to confirm improvement of the electron emission properties due to reduction in the work function at elevated temperatures.
The interest in plasmon modes dates back to the beginning of the 20th century, but recent advances in structuring, manipulating and observing on the nanometer scale have revitalized this field even though these technological advances were at first driven by the increasing demand for a semiconductor based integrated electronic components, optical applications are now receiving increasing attention. Guiding light in an integrated optical system and interfacing with electronic components remain important challenges for research and development today. Nanostructures metals are believed to be one of the key ingredients of such future optoelectronic devices.
Catalysis is one of the most important phenomena both in nature and chemistry. Photochemistry, which means chemical changes induced by absorption of light, constitutes the basis of human life. Plasmonic nanoparticles are characterized by their well-known surface catalytic properties and strong light-matter interactions.[2] Plasmonic nanoparticles are potentially useful in a number of critical technologies, including solar-to-chemical[1][3][4] and solar-to-electrical energy conversion[5], molecular characterization, imaging, lasing, and cancer tissue targeting[6]. These nanoparticles are characterized by their strong interaction with resonant photons through an excitation of surface plasmon resonance (SPR). SPR can be described as the
The use of hydrogen as a fuel requires the adoption of the fuel cells technology for their role in the reaction activity between hydrogen and hydrogen for the production of energy. The fuel cells convert more of their energy potential from the fuel source as compared to the regular gasoline fuels. The insignificance of the impact caused by the bi-products of such reactions makes it the much better option than the fossil fuels that face the threat of exhaustion. However, the adoption of hydrogen as the primary
Another of the technical setbacks which current nanotechnology is facing is the low efficiency of the energy storage of current devices, and its main causes are technical inconveniences and the relatively high cost of new technology. For example, Huang, X., Han, S., Huang, W., and Liu, X. (2013) indicate that the reason why current solar cells are not highly efficient is a mismatch in wavelengths of the peak of high energy emission of sunlight and the peak of high efficiency of these devices. Therefore, energy efficiency has become a new source of nanotechnology (Gauthier & Genet, 2014, p. 576). Supercapacitors and many of the electrodes are made of carbon-based materials (Liu et