INTERAÇÃO DE MOLÉCULAS DE TiCl3 E TiCl4 COM GRAFENO: UMA SIMULAÇÃO DE PRIMEIROS PRINCÍPIOS

• Ano de defesa: 2009
• Autor(a) principal: Santos, Marcos Andre Pereira dos
• Orientador(a): Fagan, Solange Binotto
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Franciscana
• Programa de Pós-Graduação: Mestrado Acadêmico em Nanociências
• Departamento: Biociências e Nanomateriais
• País: BR
• Palavras-chave em Português: Grafeno; Teoria do funcional da densidade; Doador; Aceitador de carga eletrônica
• Palavras-chave em Inglês: Graphene, Density functional theory, Donor; Acceptor
• Área do conhecimento CNPq: CNPQ::ENGENHARIAS
• Link de acesso: http://tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/238; http://www.tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/332

This work presents a study on the interaction of TiCl4 and TiCl3 molecules with a single- and bi-layer graphene by using the density functional theory. It is evaluated the changes in structural, electronic and magnetic properties of graphene after the adsorption of these molecules, that can behave donors or acceptors of electronic charge. We evaluated the arrangements for TiCl4 and TiCl3 molecules at three different sites using one molecule per unit cell, making use of periodic boundary conditions. In both cases the molecules have more stable chemical configuration when they are placed in the center of a hexagonal site. Significant changes in the electronic properties of the systems are observed. The molecule TiCl4 behaves like a Lewis acid (electronic charge acceptor), while in the case of the confined molecule between two graphene planes the molecule behaves as a Lewis basis (electronic charge donor). The TiCl4 on graphene remains non-magnetic in all configurations studied here. The adsorption of the molecule causes distortions in the graphene sheet, they originating a small change in the original electronic states, as a gap opening. TiCl3 molecule presents a Lewis basics behavior, which is seen directly on the lifting of the Fermi level. The TiCl3 presents a stronger binding energy when compared to the TiCl4 in graphene; this fact also shows that the electronic properties also change. It is observed that the magnetic moment of the adsorbed TiCl3 graphene associated with the spin polarization, dependent on the adsorption configuration. Therefore, this innovative work predicts the properties associated with the interaction of molecules with donors or accepted electronic charge behavior adsorbed on graphene this contributing for optimizing and developing potential application of this novel material.