Elucidating the photoinduced charge carriers mobility in photocatalysts passivated with thin conformal coatings to improve the water splitting efficiency

• Grant number: 16/23178-8
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: April 01, 2017
• End date: March 31, 2018
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Ana Flávia Nogueira
• Grantee: Saulo do Amaral Carminati
• Supervisor: Frank Erich Osterloh
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: University of California, Davis (UC Davis), United States
• Associated to the scholarship: 15/23775-3 - Metal oxides nanocomposites with reduced graphene oxide for water splitting reactions and photocatalytic reduction of CO2, BP.DR

Abstract

The synthesis and characterization of different conformal coatings on Fe2O3,BiVO4 and Cu2O semiconductors in suspension are purposed in this project. Even though the Fe2O3 and BiVO4 semiconductors absorb light in the visible range of the spectrum, theysuffer from high electron-hole recombination rate, preventing the achievement of highsolar-to-hydrogen (STH) efficiencies. In addition, their conduction band (CB) position is not suitable to reduce water into H2, requiring the application of an external bias. Besides, Cu2O has favorable band energy position for water splitting, but undergoesphotodegradation in aqueous solution. Since the main drawbacks suffered by thesesemiconductors are attributed to recombination processes of electron and holes in theirsurface and in the bulk, attempts to avoid or minimize such limitations are necessary. The use of conformal overlayers already showed the improvement in charge separation and charge-transfer processes across semiconductor-liquid interfaces and consequently increase the photocurrent. This project aims to study the effect of the passivation of Fe2O3, BiVO4 and Cu2O microparticles in suspension by thin conformal coatings of TiO2, Al2O3 and SnO2 and their performance toward water splitting reactions.A detailed investigation using surface photovoltage spectroscopy (SPS) technique will be explored to get information about the photochemical charge generation, separation and transport at interfaces.

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)

CARMINATI, SAULO AMARAL; NOGUEIRA, ANA FLAVIA. p SnO2 as thin conformal layer over BiVO4 surface for enhanced charge carrier separation towards O2 evolution from water oxidation. INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, v. 47, n. 8, p. 5211-5219, JAN 26 2022. (17/11986-5, 16/23178-8, 15/23775-3)