Surface Chemistry
Surfaces deserve a differentiated treatment because they present a significant gradient of properties besides forming the interface with molecules, generating different free energy values, electronic states, reactivities, mobility, and structures. Two main topics are covered in this line:
1) Study of Reactions Kinetics on nanomaterials surface
Two-dimensional nanometer materials (2D), such as graphene, have caused a scientific and technological revolution due to their differentiated properties. Despite their potential, some 2D materials are quite sensitive to the chemical environment in which they are inserted. In particular, oxygen (O 2 ) oxygen leads to oxidation of the material's surface, which can negatively affect its properties. However, if the material's oxidation can be controlled, it is possible to create a protective oxide layer that preserves the material below it.
To achieve such control, it is necessary to understand the reactions that occur on the materials' surface.
The dynamics of molecules on nanomaterials' surface is a controversial point in the literature, and several formalisms have already been used to adjust it to experimental results. The group works mainly in Surface Enhanced Raman Spectroscopy to elucidate the structure and study the kinetics of reactions on the surface of nanomaterials.
2) Dopagem de Materiais
In two-dimensional materials, doping is usually carried out by inducing defects in the crystalline network or forming substitutional solutions. However, these types of doping tend to be unstable, and due to the low thickness of the materials, they significantly alter their crystalline structure, which may compromise their mechanical properties and stability. The physical adsorption of organic molecules or metallic atoms on the surface of two-dimensional materials is an alternative doping method. Thus, electrophilic molecules' adsorption would lead to the creation of p-type semiconductors from nucleophilic molecules to n-type semiconductors.