TY - JOUR
T1 - Effects of preparation parameters on the characteristics of SiO2- and CoxOy-modified-TiO2 colloids prepared by hydrolysis of titanium alkoxide
AU - Brichkov, Anton S.
AU - Brichkova, Victiria Yu
AU - Paukshtis, Evgeniy A.
AU - Chen, Yu Wen
AU - Kozik, Vladimir V.
N1 - Publisher Copyright:
© 2019, Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2020/6/1
Y1 - 2020/6/1
N2 - A series of SiO2-, and CoxOy-modified-TiO2 colloids prepared by hydrolysis of titanium alkoxide were synthesized. The effects of concentrations of water, acid, cobalt chloride, and tetraethoxysilane on the characteristics of colloids were investigated. The rheologic characteristics of the sols were characterized by liquid state 29Si nuclear magnetic resonance (NMR), Raman spectroscopy, and photon correlation spectroscopy. It was found that an increase in the acid concentration from 1 to 60 mM resulted in a decrease of the particle size from 17 to 9 nm, while the diffusion coefficient increased with twofold. The presence of water shortened the formation time of sol, and the specific concentration of hydrochloric acid stabilized the colloid system. The presence of Co(II) chloride enhanced the hydrolysis rate of tetraethoxysilane and the condensation rate of hydroxy derivatives. In contrast, Ti(IV) tetra-n-butoxide showed the opposite effect, slowing these processes and decreasing the degree of condensation of siloxane chains. The results of this study can be used to optimize the composition of stable homogeneous solutions to synthesize TiO2, TiO2–SiO2, TiO2–CoxOy, and TiO2–SiO2–CoxOy sols. [Figure not available: see fulltext.].
AB - A series of SiO2-, and CoxOy-modified-TiO2 colloids prepared by hydrolysis of titanium alkoxide were synthesized. The effects of concentrations of water, acid, cobalt chloride, and tetraethoxysilane on the characteristics of colloids were investigated. The rheologic characteristics of the sols were characterized by liquid state 29Si nuclear magnetic resonance (NMR), Raman spectroscopy, and photon correlation spectroscopy. It was found that an increase in the acid concentration from 1 to 60 mM resulted in a decrease of the particle size from 17 to 9 nm, while the diffusion coefficient increased with twofold. The presence of water shortened the formation time of sol, and the specific concentration of hydrochloric acid stabilized the colloid system. The presence of Co(II) chloride enhanced the hydrolysis rate of tetraethoxysilane and the condensation rate of hydroxy derivatives. In contrast, Ti(IV) tetra-n-butoxide showed the opposite effect, slowing these processes and decreasing the degree of condensation of siloxane chains. The results of this study can be used to optimize the composition of stable homogeneous solutions to synthesize TiO2, TiO2–SiO2, TiO2–CoxOy, and TiO2–SiO2–CoxOy sols. [Figure not available: see fulltext.].
KW - Aging time
KW - Hydrolysis
KW - Si NMR
KW - Sol–gel method
KW - Titanium tetra-n-butoxide
KW - Viscosity
UR - http://www.scopus.com/inward/record.url?scp=85075360767&partnerID=8YFLogxK
U2 - 10.1007/s10971-019-05139-4
DO - 10.1007/s10971-019-05139-4
M3 - 期刊論文
AN - SCOPUS:85075360767
SN - 0928-0707
VL - 94
SP - 607
EP - 615
JO - Journal of Sol-Gel Science and Technology
JF - Journal of Sol-Gel Science and Technology
IS - 3
ER -