In situ total scattering and pair distribution function study of nanostructured medium entropy oxides

• Grant number: 23/02561-1
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: August 23, 2023
• End date: August 22, 2024
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Daniela Zanchet
• Grantee: Guilherme Boenny Strapasson
• Supervisor: Kirsten Marie Oernsbjerg Jensen
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: University of Copenhagen, Copenhagen, Denmark
• Associated to the scholarship: 20/12986-1 - Design of nickel catalysts supported on 1D TiO2/Nb2O5 nanostructures, BP.DD

Abstract

The presence of surface and bulk point defects on metal oxides drive their versatility along a diverse range of applications, such as catalysis, sensors, pharmaceutics, and energy conversion and storage. The most common defects on reducible metal oxides are oxygen vacancies, which can be associated with both intrinsic or extrinsic point defects. These oxygen vacancies, and their intrinsic oxygen mobility, play a key role in diverse research fields. By utilizing entropy as the driving force for engineering oxide materials, the deviation from traditional prediction methods and principles offers a path for new structure-property relations to be discovered, including enhanced oxygen mobility. The multi-cation approach inherent to entropy stabilized oxides (ESOs) allows for the tailoring of their properties, which can offer significant opportunities for functional material applications. However, due to their intrinsic disorder, and highly localized chemical environments a deeper investigation, with the support of a variety of local to long-range probes, needs to be performed. Thus, in this work, we aim to study medium entropy oxides composed of aliovalent cations (i.e. Ti4+, Nb5+, and Fe3+), which can lead to the charge distortion of the oxide structure and directly impact its structural and electronic properties. Conventional and advanced characterization, including in situ synthesis and annealing during X-ray total scattering experiments, are expected. One of the main goals of this BEPE project is the specialization of the Ph.D. student in the X-ray total scattering and PDF analysis, which will be conducted in the group of Prof. Kirsten M. Ø. Jensen, at the University of Copenhagen, Denmark. (AU)