Kinetic parameters involved in the photodegradation of pesticides catalyzed by TiO2 nanoparticles: comparative studies on the contribution of charge transfer and free radicals oxidation

• Grant number: 09/10998-3
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: November 01, 2009
• End date: April 30, 2013
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Cauê Ribeiro de Oliveira
• Grantee: Gabriela Byzynski Soares
• Host Institution: Embrapa Instrumentação Agropecuária. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). Ministério da Agricultura, Pecuária e Abastecimento (Brasil). São Carlos , SP, Brazil

Abstract

The concern about the efficient water management is worrying not only in agricultural and industrial areas, but it is also concern for public health and spread to a sustainable economic development. The advanced oxidative processes (AOP) are very effective methods for decontamination of water, which the TiO2 photoexcitation is highlighted, to the generation of oxidative radicals, or direct electronic transfer of the species to be oxidized to the semiconductor. Although the functionality of these processes is already established, the mechanisms involved in oxidation, the effect of doping in increasing the efficiency and durability of photocatalysis are also under study. Thus the central goal of this work is investigate the contributions of each mechanism involved in oxidation of nano-TiO2 and TiO2 doped using electrochemical and spectroscopic techniques, looking to separate the effects of each mechanism. TiO2 films immobilized on conductive substrate will be produced and their potential for oxidation of selected pesticides using different electrochemical techniques will be evaluated. It will also be evaluated the photodegradation of free radicals during the photocatalytic process using spin-trapping technique with electron paramagnetic resonance spectroscopy(EPR). Finally, the efficiency will be evaluated on the degradation of some pesticides used in large scale in sugar cane and soybean crops (ametryne, diuron and methamidophos) in order to help in the selection of improved catalysts for effluent decontamination process from those cultures. (AU)

Scientific publications

(4)

(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)

DAWSON, MARGARET; SOARES, GABRIELA BYZYNSKI; RIBEIRO, CAUE. Preparation and Photocatalytical Performance of TiO2:SiO2 Nanocomposites Produced by the Polymeric Precursors Method. Journal of Nanoscience and Nanotechnology, v. 13, n. 7, p. 5126-5133, JUL 2013. (09/10998-3)

DAWSON, MARGARET; SOARES, GABRIELA BYZYNSKI; RIBEIRO, CAUE. Influence of calcination parameters on the synthesis of N-doped TiO2 by the polymeric precursors method. Journal of Solid State Chemistry, v. 215, p. 211-218, JUL 2014. (09/10998-3)

SOARES, GABRIELA B.; BRAVIN, BRUNO; VAZ, CARLOS M. P.; RIBEIRO, CAUE. Facile synthesis of N-doped TiO2 nanoparticles by a modified polymeric precursor method and its photocatalytic properties. APPLIED CATALYSIS B-ENVIRONMENTAL, v. 106, n. 3-4, p. 287-294, AUG 11 2011. (09/10998-3)

SOARES, GABRIELA BYZYNSKI; VAZ, CARLOS M. P.; RIBEIRO, CAUE; HERMANS, IVE. Insight into the Photocatalytical Activity of TiO2 Nanoparticles Through the Electrochemical Characterization of Carbon Paste Electrodes. ELECTROCATALYSIS, v. 6, n. 1, p. 92-101, JAN 2015. (09/10998-3)