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An Understanding of the Photocatalytic Properties and Pollutant Degradation Mechanism of SrTiO 3 Nanoparticles
Author(s) -
Silva Luís F.,
Lopes Osmando F.,
Mendonça Vagner R.,
Carvalho Kele T. G.,
Longo Elson,
Ribeiro Caue,
Mastelaro Valmor R.
Publication year - 2016
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/php.12586
Subject(s) - photocatalysis , photodegradation , nanoparticle , methyl orange , rhodamine b , chemical engineering , materials science , photochemistry , adsorption , methylene blue , degradation (telecommunications) , radical , strontium titanate , transmission electron microscopy , particle size , chemistry , nanotechnology , catalysis , organic chemistry , thin film , telecommunications , computer science , engineering
Strontium titanate nanoparticles have attracted much attention due to their physical and chemical properties, especially as photocatalysts under ultraviolet irradiation. In this paper, we analyze the effect of heating rate during the crystallization process of SrTiO 3 nanoparticles in the degradation of organic pollutants. The relationship between structural, morphological and photocatalytic properties of the SrTiO 3 nanoparticles was investigated using different techniques. Transmission electron microscopy and N 2 adsorption results show that particle size and surface properties are tuned by the heating rate of the SrTiO 3 crystallization process. The SrTiO 3 nanoparticles showed good photoactivity for the degradation of methylene blue, rhodamine B and methyl orange dyes, driven by a nonselective process. The SrTiO 3 sample with the largest particle size exhibited higher photoactivity per unit area, independent of the molecule to be degraded. The results pointed out that the photodegradation of methylene blue dye catalyzed by SrTiO 3 is caused by the action of valence band holes (direct pathway), and the indirect mechanism has a negligible effect, i.e . degradation by O 2 −• and • OH radicals attack.