NANOFITAS DE GRAFENO, FOSFORENO E SILICENO PARA ADSORÇÃO DE MONÓXIDO DE CARBONO: UM ESTUDO DE PRIMEIROS PRINCÍPIOS

• Autor(a) principal: Schwarz, Stefanie Camile
• Data de Publicação: 2019
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional Universidade Franciscana
• Texto Completo: http://www.tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/805
• topic: nanomateriais, CO, teoria do funcional da densidade, campo elétrico; nanoribbons, CO, density functional theory, adsorption, electric field.; Nanociências

Nanoscience is a term used to refer to studies that seek to understand and control matter at the nanoscale. At this scale, the structures may exhibit chemical, physicochemical and behavior properties different from those observed in macro or micrometric scales. Among these materials stand out the nanoribbons for presenting several applications, as in electronic devices and sensors. Therefore, it is extremely important to understand the energetic and structural behavior of these materials. In this work the geometric and electronic properties of graphene (GNR), phosphorene (NRPBlack) and silicene (NRSi) nanoribbons were studied using first principles calculations using the density functional theory. Nanoribbons were obtained by atom-to-atom construction. Subsequently, the system was completely relaxed until reaching full convergence so that a future study of the interaction with the gas molecule carbon monoxide. This study allows to observe that depending on the nanoribbon type it is possible to obtain different electronic and magnetic characteristics in the interaction with carbon monoxide molecule, thus making the system attractive for application in sensors. In addition, an electric field was applied in the studied systems in order to observe if through the reorganization of the systems this adsorption of carbon monoxide could be increased if the energy of the gap were modulated. The energies can be repulsive where the system does not interact until attractive, where the system interacts with an energy up to -0.22 eV. When applying the electric field of intensity 0.40V / Å, for the GNR-Z nanofite, the bonding energy changes from -0.04 eV to -1.36 eV, making the system more attractive. For the SiNR_Z it is observed that with application of the electric field the system changes from repulsive to attractive, varying the energy values of binding from 0.01 eV to -0.02 eV; and 0.24 eV to -0.03 eV, and modulating the gap from 0 to 0.33 eV, changing the electronic properties from metallic to semiconductor. Finally, it is also observed that, by removing the electric field, the systems are reversible, returning to the initial characteristics.