TiO2 reduced graphene oxide composites for photocatalytic degradation in aqueous and gaseous medium

• Type: Article in International Scientific Journal
• Date: 2017-08-30

Authors

Jaqueline Suave (Author) Other; Suélen M. Amorim (Author) Other; Joana Ângelo (Author) Other; Luísa Andrade (Author) FEUP; Adélio Mendes (Author) FEUP; Regina F. P. M. Moreira (Author) Other

Journal

Title: Journal of Photochemistry and Photobiology A: Chemistry

Vol. 348

Pages: 326-336

ISSN: 1010-6030

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 8 Citations

ISI Web of Science

Scopus - 19 Citations

Scientific classification

CORDIS: Technological sciences > Engineering > Chemical engineering

Associated Projects

FCT/CAPES 4.4.1.00.01/2012 - Desenvolvimento de caraterização de fotocatalisadores compósitos de dióxido de titânio-grafeno

Other information

Authenticus ID: P-00M-ZY0

DOI: 10.1016/j.jphotochem.2017.08.064

Abstract (EN): A series of TiO2 composites loaded with 0.5-4 wt.% of reduced graphene oxide (rGO) was prepared through a combined sol-gel method and solvothermal treatment. The composites were characterized by scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), the Brunauer-Emmett-Teller (BET) method and diffuse reflectance spectroscopy (DRS). The photocatalytic performance of the prepared materials was evaluated by methylene blue discoloration in aqueous medium. The TiO2-rGO 1% composite led to an increase of ca. 11% in the pseudo-first-order rate constant, however, further increasing in rGO contents led to a decrease in the photocatalytic activity. When present in a high content, reduced graphene oxide can act as a recombination center, rather than providing a pathway for charge transfer and preventing recombination of electron-hole pairs. Subsequently, the TiO2-rGO 1% was immobilized in a vinyl-base paint and evaluated for the purification of air containing 1 ppm, of nitrogen oxide (NO). The results showed that the NO conversion was 25% and the selectivity for the transformation of NO into nitrates and nitrites was 50%. The same paint containing bare TiO2 presented an NO conversion of 35% and selectivity of 40%. Although, the abatement of NO by the composite was lower, the selectivity for ionic compounds was higher, indicating that the presence of rGO is important for the decomposition of NO under more oxidized compounds.

Type (Professor's evaluation): Scientific

No. of pages: 11