Synthesis and photocatalytic properties of heterostructured thin films: the case of BiVO4/Bi2O3 system

• Grant number: 17/17476-9
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2018
• Effective date (End): June 30, 2019
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Vagner Romito de Mendonça
• Grantee: Paulo Henrique Eleuterio Falsetti
• Home Institution: Instituto Federal de Educação, Ciência e Tecnologia de São Paulo (IFSP). Campus Itapetininga. Itapetininga , SP, Brazil

Abstract

For decades, photoactivated semiconductors have been studied regarding their application in water treatment by a process called heterogeneous photocatalysis. However, a limitation of the process is related to the fact that materials which are suitable for those applications can be excited only under UV radiation. Therefore, it becomes interesting researches about materials that can be activated under visible radiation (lower band gap values - Ebg), making possible the application of solar energy in the process. In this context, BiVO4 (Ebg of 2.4 eV) semiconductor can be applied. However, due to its electronic characteristics, it presents low photoactivity due to the fast recombination of photogenerated charges. In this way, the formation of heterostructures becomes an important alternative for the use of this material. In addition, the application as thin films enables an easy recovery of the photocatalyst material. Thus, this project proposes a preparation of heterostructured thin films of BiVO4/Bi2O3 and the study of its photocatalytic properties in the degradation of pollutants under visible radiation. Bi2O3 will be deposited via spin-coating and the film will be hydrothermally treated in the presence of BiVO4 precursors. Methylene blue photodegradation will be applied as a model reaction and the films will be further studied regarding their capability to degrade compounds such as medicines and pesticides. (AU)