共 28 条
Formation mechanisms of Ni2P nanocrystals using XANES and EXAFS spectroscopy
被引:36
作者:
Seo, Hye-Ryun
[1
]
Cho, Kye-Sung
[1
]
Lee, Yong-Kul
[1
]
机构:
[1] Dankook Univ, Dept Chem Engn, Lab Adv Catalysis Energy & Environm, Yongin 448701, South Korea
来源:
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
|
2011年
/
176卷
/
02期
关键词:
Ni2P nanocrystals;
Formation mechanism;
EXAFS;
XANES;
TRANSITION-METAL PHOSPHIDES;
TEMPERATURE;
PHOSPHORUS;
TRIOCTYLPHOSPHINE;
NANOPARTICLES;
COMPLEXES;
CATALYSTS;
NANORODS;
ROUTE;
SHAPE;
D O I:
10.1016/j.mseb.2010.10.013
中图分类号:
T [工业技术];
学科分类号:
08 ;
摘要:
Ni2P nanocrystals have been synthesized by a ligand stabilization method with adopting nickel acetylacetonate (Ni(acac)(2)) as a nickel precursor and trioctylphosphine (TOP) as a phosphorous precursor in the presence of trioctylphosphine oxide (TOPO) as a coordinating solvent. In order to better understand the formation of Ni2P nanocrystals, various synthetic routes were employed with varying the mixing order of TOP or TOPO with Ni(acac)(2) in the complexation and nucleation steps, and the phosphidation temperatures of Ni-TOP solution in TOPO. In all cases the formation of Ni2P nanocrystals having an average size in range of 5-11 nm was achieved, but with slightly larger particle distribution of ca. 11 nm being observed for the case where the TOP was injected after a nucleation of Ni-TOPO was formed. In particular, XAFS techniques of EXAXS and XANES which are effective to characterize either amorphous or crystalline materials were applied to examine the structural and electrical properties of the precursor, intermediate and final materials. This led to elucidate the role and the effect of TOP and TOPO on the formation of Ni2P nanocrystals. It is concluded that the formation of Ni2P nanocrystals proceeds through three consecutive steps of complexation, nucleation and phosphidation. In phosphidation, TOP works as a reducing agent on the Ni precursor as well as a phosphorous source through the cleavage of P-C bonds. (C) 2010 Elsevier B.V. All rights reserved.
引用
收藏
页码:132 / 140
页数:9
相关论文