Characterization and Application of Nanostructured Films Containing Au and TiO2Nanoparticles Supported in Bacterial Cellulose

Autor: Dal’Acqua, Nicolle, Mattos, Alessandra Batista de, Krindges, Israel, Pereira, Marcelo Barbalho, Barud, Hernane da Silva, Ribeiro, Sidney José Lima, Duarte, Gian Carlos Silva, Radtke, Claudio, Almeida, Luciano Costa, Giovanela, Marcelo, Crespo, Janaina da Silva, Machado, Giovanna
Zdroj: The Journal of Physical Chemistry - Part C; January 2015, Vol. 119 Issue: 1 p340-349, 10p
Abstrakt: In the last several years, the use of renewable energy sources has increased; consequently, the number of studies regarding their efficiency has also increased. It is well known that fossil and atomic fuels will not last forever and that their use contributes to environmental pollution. Thus, nanostructured thin films have attracted attention due to numerous applications, including construction of photovoltaic energy generating and photoluminescence materials. Therefore, in this study, we prepared and characterized thin films supported on bacterial cellulose that were produced using the layer-by-layer (LbL) technique. The weak polyelectrolytes, such as poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA), combined with titanium dioxide (TiO2) and gold nanoparticles (Au NPs) were used to produce flexible devices capable of producing hydrogen gas (H2) by photocatalysis. The presence of the Au NPs and TiO2in the films was confirmed using UV–vis spectroscopy, Rutherford backscattering spectrometry, and X-ray diffraction. Scanning electron microscopy was used to evaluate the surface morphology of the films, and the distribution and average size of the Au NPs were analyzed using transmission electron microscopy, which revealed sizes in the nanometer range. Finally, the thin films were analyzed using gas chromatography to evaluate the H2production by photocatalysis. Overall, the system with (PAH + TiO2) and PAA solutions at pH = 4.0 in the presence of gold salt that were reduced with ultraviolet light were more efficient due to their greater interactions with the TiO2during multilayer deposition.
Databáze: Supplemental Index