title: Multifunctional catalysts based on carbon nanotubes and titanate nanotubes for oxidation of organic compounds in biphasic systems.
abstract: Amphiphilic catalysts composed of carbon nanotubes (CNTs) and titanate nanotubes (TiNTs) have been successfully synthesized by refluxing anatase TiO2 and functionalised CNTs in concentrated NaOH solution. The prepared materials were characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis (TGA), and N2 physisorption isotherms. The catalytic activity of the synthesized composites was first evaluated in the oxidation of methyl yellow (MY) using H2O2 as oxidant in a single liquid phase system and in a biphasic water/oil mixture. The results of these experiments indicated that the catalytic activities of nanocomposites were very similar in the single liquid-phase oxidation. However, the modification of TiNTs with CNTs led to a substantially enhanced MY oxidation in the biphasic system. The nanocomposites show excellent interaction with both hydrophilic and hydrophobic compounds and thus stabilise emulsions. Under biphasic conditions, the catalysts can be easily separated and recycled, retaining catalytic activity even after eight runs. Additionally, the hybrid materials show superior catalytic activity and selectivity in the biphasic oxidation of benzyl alcohol with H2O2, as compared to pure TiNTs.
authors.affiliation: Centro Federal de Educação Tecnológica de Minas Gerais, Departamento de Química, Av. Amazonas, 5253, Belo Horizonte, MG, Brazil.
authors.forename: S R A
authors.initials: SRA
authors.lastname: Santos
authors.affiliation: Centro Federal de Educação Tecnológica de Minas Gerais, Departamento de Química, Av. Amazonas, 5253, Belo Horizonte, MG, Brazil.
authors.forename: I S
authors.initials: IS
authors.lastname: Jardim
authors.affiliation: Centro Federal de Educação Tecnológica de Minas Gerais, Departamento de Química, Av. Amazonas, 5253, Belo Horizonte, MG, Brazil.
authors.forename: H A
authors.initials: HA
authors.lastname: Bicalho
authors.affiliation: Centro Federal de Educação Tecnológica de Minas Gerais, Departamento de Química, Av. Amazonas, 5253, Belo Horizonte, MG, Brazil.
authors.forename: I
authors.initials: I
authors.lastname: Binatti
authors.affiliation: Centro de Desenvolvimento da Tecnologia Nuclear, Serviço de Nanotecnologia, Av. Antônio Carlos, 6627 Belo Horizonte, MG, Brazil.
authors.forename: E M B
authors.initials: EMB
authors.lastname: Sousa
authors.affiliation: Centro de Desenvolvimento da Tecnologia Nuclear, Serviço de Nanotecnologia, Av. Antônio Carlos, 6627 Belo Horizonte, MG, Brazil.
authors.forename: A M
authors.initials: AM
authors.lastname: Peres
authors.affiliation: Universidade Federal de Minas Gerais, Departamento de Bioquímica e Imunologia, Av. Antônio Carlos, 6627 Belo Horizonte, MG, Brazil; Instituto Nanocell, Rua Sto. Antônio, 420 Divinópolis, MG, Brazil.
authors.forename: R R
authors.initials: RR
authors.lastname: Resende
authors.affiliation: Centro Federal de Educação Tecnológica de Minas Gerais, Departamento de Química, Av. Amazonas, 5253, Belo Horizonte, MG, Brazil. Electronic address: eudesquimica@hotmail.com.
authors.forename: E
authors.initials: E
authors.lastname: Lorençon
keywords: Amphiphilic catalysts; Carbon nanotubes; Hydrogen peroxide; Oxidation; Titanate nanotubes