Control of electronic properties of columnar hematite nanostructure by double transition elements insertion for photoelectrocatalitic water splitting

• Grant number: 21/07459-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Effective date (Start): November 01, 2021
• Effective date (End): October 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Flavio Leandro de Souza
• Grantee: Karen Cristina Bedin
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovações (Brasil). Campinas , SP, Brazil
• Host Company: Universidade Estadual de Campinas (UNICAMP). Instituto de Química (IQ)
• Associated research grant: 17/11986-5 - Research Division 1 - Dense Energy Carriers, AP.PCPE

Abstract

The present research proposal focuses on the preparation of new electrodes based on vertically oriented hematite nanostructures, combining two elements (titanium and zirconium or titanium and niobium), for application in the generation of carbon-free alternative energy from the water molecule photoelectrolysis induced by sunlight. The elements were selected based on their physicochemical characteristics, discussed in this proposal, which can provide improvements in the electronic and structural properties of hematite. The aim is to develop a method to reduce electronic problems of hematite, resulting from inefficient photogenerated charge separation processes, without negatively interfering in the light absorption properties and in the efficiency of promoting the surface chemical reactions involved in the water molecule photoelectrolysis. The engineering study of hematite electrode interfaces will be primordial and carefully executed, from pre-defined experimental steps, based on microwave-assisted hydrothermal synthesis and morphological, optical, structural and electrochemical characterization techniques. After the methodological design of the best experimental approach to be followed to obtain an efficient electrode, its performance as photoanode in the water molecule splitting reaction will be evaluated in alkaline environment, using a sunlight simulator (global AM 1.5 filter, 100 mW cm2) together with a potentiostat. In view of the proposed, the research project presented will be linked to Division 1 - Dense Energy Carriers (DEC), which belongs to the Shell-FAPESP 17/11986-5 process, in the area that is committed to the development of nanostructured materials, based on the investigation of their inherent characteristics, to modify them to enhance the separation and transport of photogenerated charges at the interfaces. Furthermore, the quantification of hydrogen generated by photoelectrolysis may be carried out using a newly acquired gas chromatograph to compose the infrastructure of the laboratory. (AU)