Effect of dopants in semiconductor nanostructures and their impact on photocatalytic performance

• Grant number: 13/05471-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2013
• End date: September 27, 2017
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Flavio Leandro de Souza
• Grantee: Waldemir Moura de Carvalho Junior
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil

Abstract

The use of iron oxide as photoanodes in photoelectrochemical cells for hydrogen generation has been intensively studied in recent years. In this sense, a significant number of research groups have sought new methods of synthesis for obtaining nanostructures with different morphologies in order to improve the efficiencies of these devices. In this PhD project, nanostructures of iron oxide in the form of vertically oriented rods on transparent conductive substrates are synthesized by a method that involves hydrothermal conditions. The main focus of this project is to understand the basic parameters that control the photocatalytic performance of hematite produced by the proposed method. Is still studied the influence of dopants and the pre-deposition layers (before the main layer of iron oxide) compounds such as SnO2, TiO2 and SiO2, in structural, morphological, physical-chemical and performance of photocatalytic materials modified. In studies of this system in the group has been found that the annealing temperature plays an important role in the properties of the material, determining the balance between the desired morphology and the percentage of conversion of hydrated phase to phase hematite. More recently, using different substrates such as support of nanostructures as well as some changes in the hydrothermal method has resulted in photoanodes with excellent photocatalytic performance. Thus, the understanding of these new results from changes in the synthetic method (under-layers, dopants and exchange of precursors) be essences to produce materials with properties and devices with improved performance and more competitive.

Scientific publications

(5)

(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)

CARVALHO-, JR., WALDEMIR M.; SOUZA, FLAVIO L.. Thermal enhancement of water affinity on the surface of undoped hematite photoelectrodes. SOLAR ENERGY MATERIALS AND SOLAR CELLS, v. 144, p. 395-404, JAN 2016. (13/05471-1, 12/19926-8, 11/19924-2, 13/07296-2)

ITO, NATHALIE MINKO; CARVALHO, JR., WALDEMIR MOURA; MUCHE, DERECK NILLS FERREIRA; CASTRO, RICARDO HAUCH RIBEIRO; DALPIAN, GUSTAVO MARTINI; SOUZA, FLAVIO LEANDRO. High temperature activation of hematite nanorods for sunlight driven water oxidation reaction. Physical Chemistry Chemical Physics, v. 19, n. 36, p. 25025-25032, SEP 28 2017. (13/05471-1, 11/19924-2, 16/02157-2, 13/07296-2)

CARVALHO-JR, WALDEMIR M.; SOUZA, FLAVIO L.; SANTOS, SYDNEY FERREIRA; BOBET, JEAN-LOUIS. Rapid microwave-assisted synthesis of zirconium aluminide. Materials Chemistry and Physics, v. 211, p. 249-257, JUN 1 2018. (13/05471-1, 13/07296-2)

CARVALHO, JR., WALDEMIR M.; SOUZA, FLAVIO L.. Hematite Surface Activation by Chemical Addition of Tin Oxide Layer. ChemPhysChem, v. 17, n. 17, p. 2710-2717, SEP 5 2016. (13/05471-1, 13/07296-2, 11/19924-2, 14/50516-6)

CARVALHO-JR, W. M.; MENDONCA-FERREIRA, L.; COSTA, F. N.; FERREIRA, F. F.; MUCHE, D. N. F.; TOFANELLO, R. A.; CASTRO, R. H. R.; SOUZA, F. L.. Annealing control of hydrothermally grown hematite nanorods: Implication of structural changes and Cl concentration on weak ferromagnetism. Journal of Alloys and Compounds, v. 799, p. 83-88, AUG 30 2019. (16/02157-2, 13/05471-1, 13/07296-2, 11/19924-2)