A hydrothermal peroxo method for preparation of highly crystalline silica-titania photocatalysts
authors Krivtsov, I; Ilkaeva, M; Avdin, V; Khainakov, S; Garcia, JR; Ordonez, S; Diaz, E; Faba, L
nationality International
journal JOURNAL OF COLLOID AND INTERFACE SCIENCE
author keywords Peroxo complex; Peroxo titanic acid; Crystallinity; Anatase; SiO2-TiO2
keywords SOL-GEL ROUTE; ANATASE TIO2; MIXED OXIDES; HETEROGENEOUS PHOTOCATALYSIS; COMPOSITE NANOPARTICLES; PEROXOTITANIUM COMPLEX; DIOXIDE; ACID; NANOCOMPOSITES; NANOCRYSTALS
abstract A new completely inorganic method of preparation of silica-titania photocatalyst has been described. It has been established that the addition of silica promotes crystallinity of TiO2 anatase phase. Relative crystallinity and TiO2 crystal size in the silica-titania particles increase with the silica content until SiO2/TiO2 molar ratio of 0.9, but at higher molar ratios they start to decrease. The single-source precursor containing peroxo titanic (PTA) and silicic acids has been proved to be responsible for high crystallinity of TiO2 encapsulated into amorphous silica. It has been proposed that peroxo groups enhance rapid formation of crystalline titania seeds, while silica controls their growth. It has been concluded from the TEM that the most morphologically uniform anatase crystallites covered with SiO2 particles are prepared at SiO2/TiO2 molar ratio of 0.4. This sample, according to Si-29 NMR, also shows the high content of hydroxylated silica Q(3) and Q(2) groups, and it is the most photocatalytically active in UV-assisted decomposition of methylene blue among the tested materials. It has been determined that the increase in the amount of the condensed Q(4) silica in the mixed oxides leads to the decrease in photocatalytic performance of the material, despite its better crystallinity. High crystallinity, low degree of incorporation of Ti atoms in SiO2 in the mixed oxide and adsorption of methylene blue in the vicinity of photoactive sites on the hydroxylated silica have been considered as the main factors determining the high degradation degree of methylene blue in the presence of silica-titania. (C) 2014 Elsevier Inc. All rights reserved.
publisher ACADEMIC PRESS INC ELSEVIER SCIENCE
issn 0021-9797
year published 2015
volume 444
beginning page 87
ending page 96
digital object identifier (doi) 10.1016/j.jcis.2014.12.044
web of science category Chemistry, Physical
subject category Chemistry
unique article identifier WOS:000349134100013
link https://www.sciencedirect.com/science/article/pii/S0021979714009977?via%3Dihub
  ciceco authors
  impact metrics
journal analysis (jcr 2017):
journal impact factor 5.091
5 year journal impact factor 4.281
category normalized journal impact factor percentile 77.891
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg