Journal of Sol-Gel Science and Technology
SOL-GEL AND HYBRID MATERIALS FOR CATALYTIC, PHOTOELECTROCHEMICAL
AND SENSOR APPLICATIONS
Novel synthetic route for low-cost carbon-modiﬁed TiO
enhanced visible light photocatalytic activity: carbon content and
Nicolas Perciani de Moraes
Maria Lucia Caetano Pinto da Silva
Tiago Moreira Bastos Campos
Gilmar Patrocínio Thim
Liana Alvares Rodrigues
Received: 5 February 2018 / Accepted: 17 May 2018
© Springer Science+Business Media, LLC, part of Springer Nature 2018
The aim of this study was the development of low-cost tannin-formaldehyde xerogel/TiO
(XTi-w) and carbon xerogel/TiO
(XTiC-w) photocatalysts. The materials used as precursors were recycled titanium scraps and black wattle tannin extract,
highlighting the low-cost approach employed in the synthesis. The materials were characterized by diffuse reﬂectance
spectroscopy, scanning electron microscopy, dispersive energy spectrophotometry, X-ray diffractometry, infrared and
Raman spectroscopy. X-ray diffractometry showed that the XTiC-w have tetragonal crystalline structure (anatase), whereas
the XTi-w has an amorphous structure. The Raman and infrared analysis also showed the presence of titanium dioxide in the
composition of both XTi-w and XTiC-w. XTi-w and XTiC-w showed photocatalytic activity at the visible wavelength.
Titanium dioxide displayed no photocatalytic activity at the visible wavelength. The XTi-60 composite displayed the highest
efﬁciency in the removal of the methylene blue from the system, as well as good reusability properties. The radicals with
higher inﬂuence in the photocatalytic reaction mechanism are the photo generated electron and the singlet oxygen molecule.
The effect of the heat treatment is negative on the photocatalytic properties of the hybrids produced, due to the removal of
acid sites, adsorbed water and OH surface groups.
The graphical abstract displays an illustration of the materials obtained in this work and their respective efﬁciency in the
adsorption and photocatalytic degradation of methylene blue under visible light.
Hybrids were produced using low-cost materials, such as titanium scraps and tannin
Both hybrid materials showed photocatalytic activity at the visible wavelength
Heat treatment is negative on the photocatalytic properties of the hybrids
Reaction mechanism is controlled by trapped electrons and singlet oxygen molecules
* Liana Alvares Rodrigues
Departamento de Engenharia Química, Escola de Engenharia de
Lorena-EEL/USP,, Estrada Municipal do Campinho S/N,
Lorena, São Paulo, CEP 12602-810, Brazil
Instituto Tecnológico de Aeronáutica-ITA/CTA,, Praça Mal.
Eduardo Gomes 50, São José dos Campos, São Paulo, CEP 12228-