NANOSYSTEMS: PHYSICS, CHEMISTRY, MATHEMATICS, 2018, 9 (2), P. 266–278
The microstructure effect on the Au/TiO2 and Ag/TiO2 nanocomposites photocatalytic activity
D. A. Kozlov – Faculty of Materials Science, Lomonosov Moscow State University, 173 Leninskiye gory, Moscow, 119991, Russia; kozlov@inorg.chem.msu.ru
V. A. Lebedev – Faculty of Materials Science, Lomonosov Moscow State University, 173 Leninskiye gory, Moscow, 119991; Faculty of Chemistry, Lomonosov Moscow State University, 13 Leninskiye gory, Moscow, 119991, Russia; vasya_lebedev@mail.ru
A.Yu. Polyakov – Faculty of Materials Science, Lomonosov Moscow State University, 173 Leninskiye gory, Moscow, 119991, Russia; a.yu.polyakov@gmail.com
K. M. Khazova – Faculty of Materials Science, Lomonosov Moscow State University, 173 Leninskiye gory, Moscow, 119991, Russia; khazovakm@gmail.com
A.V. Garshev – Faculty of Materials Science, Lomonosov Moscow State University, 173 Leninskiye gory, Moscow, 119991; Faculty of Chemistry, Lomonosov Moscow State University, 13 Leninskiye gory, Moscow, 119991; Baikov Institute of Metallurgy and Material Science RAS, 49 Leninskiy prospekt, Moscow, 119334, Russia; garshev@inorg.chem.msu.ru
In this work the systematic study of the Au/TiO2 and Ag/TiO2 nanocomposites was evaluated. Aeroxide P25 preparation was taken as a titania precusor. Composites were obtained using different wet chemistry techniques: impregnation by previously prepared nanoparticles(NPs) sols, insitu reduction by sodium borohydride, sodium citrate and UV irradiation. The varying of the synthesis method due to the reduction rate differences results in the different interaction between metal NPs and titanium dioxide, and hence different metal/TiO2 contacts were observed. All the obtained samples were analyzed by XRD, TRS, SEM with EDX and TEM with EDX. According to the statistical analysis of the TEM images the correlation between the metal NPs rate formation and their anisotropy was shown, which may allow us to consider the anisotropy as a descriptor of the contact quality. Combining the results of the optical spectroscopy with the NPs TEM statistical analysis, we confirmed the correlation between observable anisotropy and the contact quality. Finally, the effect of the synthesis method on the photocatalytic activity (PCA) of nanocomposites was shown. Since the work functions of Au and Ag differ, the opposite effects on PCA are expected. Thus, in the case of the Au/TiO2 nanocomposites, the positive effect associated with NPs anisotropy on the PCA was demonstrated. Alternatively, in the case of the Ag/TiO2 nanocomposites the PCA evolution was detected only in the case of small NPs formation.
Keywords: photocatalysis, titania, nanocomposites, TiO2, gold nanoparticles, silver nanoparticles, anisotropy.
PACS 61.46.+w,68.37.Lp
DOI 10.17586/2220-8054-2018-9-2-266-278
