Oxide and semiconductor nanowires: effects of quantum confinement, heterostructures and hydrogen production

• Grant number: 11/15683-0
• Support Opportunities: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): December 01, 2011
• Effective date (End): May 31, 2014
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Gustavo Martini Dalpian
• Grantee: Aline Luciana Schoenhalz
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil

Abstract

This project aims to investigate, through first principles methods, the properties of oxide nanowires including ZnO, TiO2, In2O3, SnO2 and others semiconductors. We intend to study unusual effects present in these nanostructures, originated from quantum confinement and the surfaces, since they are the main causes of the novel properties of these nanostructured materials. We also will analyze heterostructures in these nanowires, where part of nanowire is a semiconductor material (Si, Ge, GaN) and another part is an oxide material. This allows differences in nanowire composition along the wire or in the radial direction, in such a way that the band offset leads to an efficient charge separation. Lastly, we hope to understand the mechanism that makes possible the application of these nanostructures to hydrogen production from water and sunlight, and also develop quantum molecular dynamics calculus to correctly describe and understand the processes at semiconductor surface. This is possible through the photoelectrochemical decomposition process, which has a semiconductor electrode and a metallic counter-electrode immersed in an aqueous solution to split the water molecule in the semiconductor surface. Since the semiconductor is nanostructured, there is a huge superficial area in contact with the water and it is expected that this will increase the efficiency of the cell. We also plan to interact with experimental groups at UFABC working in this kind of materials. (AU)