Quenching of Photoactivity in Phthalocyanine Copper(II)-Titanate Nanotube Hybrid Systems

Author(s)

Alves, W. ^[1] ; Ribeiro, A. O. ^[1] ; Pinheiro, M. V. B. ^[2] ; Krarnbrock, K. ^[2] ; El Haber, F. ^[3] ; Froyer, G. ^[3] ; Chauvet, O. ^[3] ; Ando, R. A. ^[4] ; Souza, F. L. ^[1] ; Alves, W. A. ^[1]

Affiliation

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210170 Santo Andre, SP - Brazil

^[2] Univ Fed Minas Gerais, ICEx, Dept Fis, BR-31270901 Belo Horizonte, MG - Brazil

^[3] Univ Nantes, CNRS, Inst Mat Rouxel IMN, F-44322 Nantes 03 - France

^[4] Univ Sao Paulo, Inst Quim, BR-05513970 Sao Paulo - Brazil

• Document type: Journal article
• Source: Journal of Physical Chemistry C; v. 115, n. 24, p. 12082-12089, JUN 23 2011.
• Web of Science Citations: 4

Abstract

Titanate nanotubes (TiNTs) were obtained by hydrothermal treatment of anatase powder in aqueous NaOH solution and then modified with 2,9,16,23-tertracarboxyl phthalocyanine copper(H) (CuPc). This hybrid organic inorganic nanoscopic system was characterized by X-ray diffraction, microscopy, and spectroscopy. Transmission electron microscopy (TEM) images of pure and modified TiNTs revealed multiwall structures with an average outer diameter of 9 nm and a length of several hundred nanometers. The tubular morphology of the TiNTs was covered with CuPc-film. The amount of CuPc adsorbed onto the TiNTs was quantified by electron paramagnetic resonance (EPR). Using the same technique and spin-trapping methodology, the photogeneration of reactive oxygen species (ROS) from the TiNTs was systematically investigated. A drastic quenching of photoactivity was observed in the CuPc/TiNT hybrid system. Electron transfer from excited CuPc states to the TiNT conduction band followed by electron recombination may be the cause of this quenching. (AU)

• FAPESP's process: 08/57805-2 - Institute of Bioanalytics
• Grantee: Lauro Tatsuo Kubota
• Support Opportunities: Research Projects - Thematic Grants