Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Adsorption of diatomic greenhouse gases and compounds using molybdenum disulphide monolayers: First principles studies(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-11-27) Gutiérrez Rodríguez, Josué; REYES RETANA, JOSE ANGEL; 2168988; Miralrio Pineda, Alan Joel; puemcuervo, emipsanchez; Reyes Retana, José Angel; School of Engineering and Sciences; Campus Estado de México; Medina Medina, Dora IlianaCurrently, the amount of greenhouse gases has increased dramatically due to human activities. Its negative impacts could be mitigated by the research of novel materials. Restrictions of size, in one or more dimensions, changes some properties of materials such as bidimensional materials (2D). The adsorption of pollutant gases on graphene has shown stability issues. However, some studies suggest that the adsorption on molybdenum disulfide monolayer is stable, although its surface is chemically inert and needs to be activated. Molybdenum disulfide monolayer can be chemically activated by point defects, for example, small clusters of coinage metals (Au, Ag or Cu). Dispersion-corrected density functional theory will allow analyzing some properties of group 11 small clusters embedded into MoS2 monolayers and their interaction with greenhouse gases and common atmospheric components. The chemical bonding was analyzed in terms of projected density of states and Bader charges. Simulation results will contribute to the production of theoretical data needed for a better understanding of physical-chemical properties and hence the development of greenhouse gas mitigation systems. Findings will be communicated to contribute to the research of novel methods for the reduction of greenhouse gas levels by using this modified bi dimensional material.
- Theoretical study on electronic and optical properties of chemically gated circum-1-coronene with metal oxide nanoclusters(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-06-20) Guzmán González, Irvin Fernando; GUZMAN GONZALEZ, IRVIN FERNANDO; 887326; Mallar, Ray; emijzarate/puemcuervo; Bonilla, Jaime; School of Engineering and Sciences; Campus Monterrey; Palma, JulioGraphene is a highly versatile material due to their mechanical and electrical properties. It is a 2-dimensional carbon material with 1 atom of thickness fully of conjugated bonding. Because of its structural and bonding con guration some derivatives of graphene as graphene nanoribbons (GNR) has been focused for developing electronic devices at a molecular scale. Molecular electronics is the eld that studies the electronic and thermal properties of single-molecule junctions. It has the goal of developing typical electronic devices, such as diodes, transistors, switches, and thermoelectric devices at the molecular scale. Nowadays, the miniaturization of electronic components has become a challenge for future developments of microprocessors, sensors, and micro-machines. A crucial step to overcome this challenge is to comprehend the behavior of electronic dynamics at a molecular level. On molecular junctions, where the classical system setup is Metal-Molecule-Metal (MMM), several factors can change or gate the charge transport through the device. One of them is chemical gating. Chemical gating is based on modifying the orbital energies of the base molecule through an adsorption or chemical bond with other molecules or reactants. The change in the base molecule a ects its electronic properties. This gives versatility for more options and tuneability in terms of developing new molecular electronic devices. This project will focus on the theoretical study of a system composed of a graphene quantum dot (Circum-1-coronene) and their interaction with the metal oxide clusters of TiO2 and ZnO. The calculation of thermodynamical, optical, electronic properties with density functional theory (DFT) for the graphene quantum dot (GQD) and their interaction with metal oxide clusters. The achievement of this goal was done implementing a systematic modi cation to the graphene base molecule, optimizing and characterizing the thermodynamical interaction with the titanium dioxide and zinc oxide clusters of sizes from 1 unit to 5 and 6 units, respectively. We also analyzed optical properties through the calculation of excited state to obtain UV-vis absorption spectra. Lastly to calculate their e ect on the electron transport molecular junction, MMM was designed. The metal electrodes were gold nanowires and the base molecule was the GQD (Circum-1-Coronene). In the arrangement of the molecular junction, the main plane of the GQD is parallel to the ow of the current and its modi cation is with the adsorption of the TiO2 and ZnO clusters. With the previous methodology, we found free Gibbs energy of adsorption in the order of 180:8kJmol1 and 151kJmol1 for Cir1cor(ZnO)6 and Cir1cor. (TiO2)5 hybrid systems. Also we generate a set of molecular characteristics that may permit the development of a optical sensor capable of checking if the metal oxide clusters are adsorbed on the GQD. Lastly we nd the result to modulate the conductance of the GQD between a range of 25% to 75% of the original isolated conductance. This calculations may help the research and development for the design of future molecular electronic devices.