Quantum modeling combined with experiments to unravel the influence of interface defects on conduction mechanisms in vanadium-doped CeO2 semiconductors

• Grant number: 24/20227-4
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: February 03, 2025
• End date: February 02, 2026
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Julio Ricardo Sambrano
• Grantee: Julio Ricardo Sambrano
• Visiting researcher: Miguel Adolfo Ponce
• Visiting researcher institution: Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil
• Associated research grant: 13/07296-2 - CDMF - Center for the Development of Functional Materials, AP.CEPID

Abstract

The project consists of studying the electronic, structural and sensor properties of cerium oxide (CeO2)-based matrices doped with vanadium (V). For this purpose, it is proposed that research activities combining computational modeling and simulation with experimental approaches be developed. The main objective is to investigate the influence of different types of atomic-scale defects on the optical, electronic and structural properties of pure CeO2 and CeO2 doped with different concentrations of V. The dependence of the properties of nanoparticles, synthesized via microwave-assisted solvothermal synthesis, on their morphology will also be evaluated. The proposed systems will be investigated primarily for the detection of toxic gases, such as CO. On the other hand, to study the defect structure of the synthesized samples, the Positron Annihilation Spectroscopy (PALS) technique will be used in conjunction with X-ray Excited Photoelectron Spectroscopy (XPS), Electron Paramagnetic Resonance Spectroscopy (EPR) and Complex Impedance Spectroscopy (CIS) which will provide essential information about the defect structure and conduction mechanisms of the synthesized nanostructures. Sensor films will be prepared from the synthesized samples and deposited on alumina substrates coated with conductive interdigital tracks. The performance of the sensor regarding their sensitivity, response and recovery time, selectivity and working temperature will be evaluated against carbon monoxide, with controlled temperature and atmospheres. The experimental results will be analyzed and their interpretations will be evaluated and compared with results obtained through theoretical models based on simulations via density functional theory, in particular, demonstrating the detection of CO. Simulations will be performed to determine the structural electronic properties of each face of the nanoparticles obtained under different parameters and/or synthesis methods. (AU)