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Photocatalytic Activity of Ag-TiO 2 Composites Deposited by Photoreduction under UV Irradiation

2018; Hindawi Publishing Corporation; Volume: 2018; Linguagem: Inglês

10.1155/2018/6080432

1687-529X

Carlos Díaz‐Uribe, Jose Viloria, Lorraine Cervantes, William Vallejo, Karen Navarro, Eduard Romero, César Quiñones,

Advanced Nanomaterials in Catalysis

In this work, we synthesized Ag nanoparticles on TiO 2 thin films deposited on soda lime glass substrates. Ag nanoparticles were synthesized by photoreduction under UV irradiation silver nitrate solution. X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) measurements were used for physicochemical characterization. The structural study showed that all samples were polycrystalline, main phases were anatase and rutile, and no additional signals were detected after surface modification. Raman spectroscopy suggested that silver aggregates deposited on the TiO 2 films could exhibit the surface plasmon resonance (SPR) phenomenon; XPS and SEM analysis confirmed TiO 2 film morphological modification after photoreduction process. Photocatalytic degradation of methylene blue (MB) was studied under UV irradiation in aqueous solution, and, besides, pseudo-first-order model was used to obtain kinetic information about photocatalytic degradation. Results indicated that Ag-TiO 2 showed an important increase in photocatalytic activity under UV (from 20% to 35%); finally, Ag-TiO 2 thin films had k a p p value 2.4 × 10 −3 ± 0.003 min −1 of 1.8 times greater than the k a p p value 1.3 × 10 −4 ± 0.0004 min −1 of TiO 2 thin films.