TY - JOUR
T1 - Core–shell structure formation strategy with hydrothermal synthesis
T2 - Importance of seeds, precursor concentration, and heterogeneous reaction
AU - Yoko, Akira
AU - Okabe, Sho
AU - Seong, Gimyeong
AU - Tomai, Takaaki
AU - Adschiri, Tadafumi
N1 - Funding Information:
This study was supported by grants from the Japan Society for the Promotion of Science (JSPS) KAKENHI (Grant Number, JP16H06367) , the New Energy and Industrial Technology Development Organization (NEDO) , WPI – Advanced Institute for Materials Research (WPI-AIMR) , Tohoku University established by the World Premier International Research Center Initiative (WPI) of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) , and process science project, MEXT, Japan.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/5/1
Y1 - 2020/5/1
N2 - While using the titanium organic complex as a starting material under widely various seed concentrations and temperature conditions, this study examined the reaction kinetics of titanium oxide formation on nickel particles. Homogeneous and heterogeneous nucleation depending on temperature were studied from the perspective of reaction engineering for core–shell type particle design. Homogeneous nucleation and the growth rate were comparable: around 250 °C with 4.8 wt% nickel loading. Heterogeneous reaction is dominant by lowering the temperature or increasing the seed amount. Moreover, acceleration of titanium oxide formation using nickel seeds and further acceleration were found after covering nickel with titanium oxide. Homogeneous amorphous shell formation was confirmed with nanoscale analysis, which is expected to be promising for applications such as multilayer ceramic capacitors.
AB - While using the titanium organic complex as a starting material under widely various seed concentrations and temperature conditions, this study examined the reaction kinetics of titanium oxide formation on nickel particles. Homogeneous and heterogeneous nucleation depending on temperature were studied from the perspective of reaction engineering for core–shell type particle design. Homogeneous nucleation and the growth rate were comparable: around 250 °C with 4.8 wt% nickel loading. Heterogeneous reaction is dominant by lowering the temperature or increasing the seed amount. Moreover, acceleration of titanium oxide formation using nickel seeds and further acceleration were found after covering nickel with titanium oxide. Homogeneous amorphous shell formation was confirmed with nanoscale analysis, which is expected to be promising for applications such as multilayer ceramic capacitors.
KW - Amorphous titanium oxide
KW - Core–shell particles
KW - Growth kinetics
KW - Homo/heterogeneous nucleation
KW - Hydrothermal synthesis
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U2 - 10.1016/j.supflu.2019.104749
DO - 10.1016/j.supflu.2019.104749
M3 - Article
AN - SCOPUS:85077989899
VL - 159
JO - Journal of Supercritical Fluids
JF - Journal of Supercritical Fluids
SN - 0896-8446
M1 - 104749
ER -