Engineering Interfaces on Hematite Electrodes for Sunlight Assisted Water Oxidation.

• Grant number: 19/01470-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: August 01, 2019
• End date: December 16, 2019
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Flavio Leandro de Souza
• Grantee: Dereck Nills Ferreira Muche
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil
• Company: Universidade Estadual de Campinas (UNICAMP). Instituto de Química (IQ)
• Associated research grant: 17/11986-5 - Generation and storage of New Energy: bringing technological development for the country, AP.PCPE

Abstract

The aim of this proposal lies in the synthesis and characterization of ultrathin nanocrystalline iron oxide electrodes in the hematite phase (30 - 100 nm), in their pure and modified states, by the deposition of different oxides of transition metals (eg SnO2, TiO2, etc.). Ultrathin pure and modified nanocrystalline Fe2O3 electrodes will be obtained from an alcoholic solution composed of Fe3+ complexed polymeric solution synthesized via Pechini method, followed by deposition via "Spin-coating". This methodology is especially desirable due to its simplicity in terms of equipment and processes, good reproducibility and promising scale-up and industrial potential. The performance of the electrodes will be evaluated based on its gain in efficiency in terms of Solar radiation to H2 conversion resulted from photoelectrolysis of water. Hence, the first part of this project will focus on: i) the preparation and engineering of interfacial nanostructuration of hematite electrodes, ii) electrochemical and electrical impedance spectroscopy (simulating application field under dark and light), to investigate the charge transportation along the interfaces (substrate / hematite film and conductive layer / electrolyte) to complement the dynamics of charge transport at the interface, evaluated also by transient absorption spectroscopy, iii) processes and transformations at the surfaces during operation will be monitored by photo-spectro-electrochemistry and X-ray excitation photoelectron spectroscopy, besides Atomic Force, Transmission and Scanning Electron microscopy. Collaboration with researcher groups specialized in simulation are already happening and also scheduled for the next year, for helping us to elucidate a better comprehension of charge transport mechanisms which, in fact, is one of the main limitations of hematite as photo catalytic material. The second part of this project focuses on the preparation of large size hematite electrode towards industrial applications. This part will be synergistically connected with the previous fundamental investigation, where the characteristics of the electrode in laboratorial scale are compared with large size prototypes. This will be carried out at the Prof. Dr. Sanjay Mathur laboratory in Cologne, Germany. Lastly, this project will be linked to the Project: Shell-FAPESP (Process # 17/119865), specifically with the Division 1 (Dense Charge Carriers), where the focus are toward the comprehension of the fundamental characteristics of charge transport at the interfaces as well as morphological, optical and electronic properties. Moreover, the network and relationships with International research groups as it is being proposed here, will bring the technology of the prototypes for such photoelectrochemical devices semiconductors, here studied. Experimental work will be conducted primarily at UFABC's Alternative Energy and Nanomaterials Laboratory (LEAN), but also, projects are planned that involve the infrastructure of the collaborating groups through the recently approved and current projects. The second part involving the prototype production will be conducted under supervision of Prof. Sanjay Mathur in Germany.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MUCHE, DERECK N. F.; CARMINATI, SAULO A.; NOGUEIRA, ANA F.; SOUZA, FLAVIO L.. Engineering interfacial modification on nanocrystalline hematite photoanodes: A close look into the efficiency parameters. SOLAR ENERGY MATERIALS AND SOLAR CELLS, v. 208, MAY 2020. (17/11986-5, 19/01470-7)