A kinetic study of the phase conversion of layered cobalt hydroxides

被引:51
作者
Du, Yi [1 ]
Ok, Kang Min [1 ]
O'Hare, Dermot [1 ]
机构
[1] Univ Oxford, Chem Res Lab, Dept Chem, Oxford OX1 3TA, England
关键词
D O I
10.1039/b809085h
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
A kinetic study of the phase conversions of three layered alpha-type cobalt hydroxides, two pink forms {Co(OH)(1.4)(NCO)(0.6)center dot 0.6H(2)O, Co(OH)(1.5)(NO(3))(0.5)center dot 0.6H(2)O} and a green form {Co(OH)(1.6)Cl(0.4)center dot 0.4H(2)O} to a brucite-like beta-Co(OH)(2) in the presence of NaOH have been investigated using time-resolved, in situ energy-dispersive X-ray diffraction (EDXRD) and time-resolved, in situ simultaneous small/wide angle X-ray scattering (SAXS/WAXS). The kinetic data have been modelled using the Avrami-Erofe'ev model. This analysis suggests that conversion of Co(OH)(1.4)(NCO)(0.6)center dot 0.6H(2)O to beta-Co(OH)(2) follows a two-dimensional diffusion-controlled model while the conversion of Co(OH)(1.6)Cl(0.4)center dot 0.4H(2)O to beta-Co(OH)(2) is best modelled by a phase-boundary-controlled process. The in situ SAXS/WAXS experiments on the conversion of Co(OH)(1.6)Cl(0.4)center dot 0.4H(2)O to beta-Co(OH)(2) suggests that an Ostwald ripening model is obeyed during the final stages of the reaction. The transformation from Co(OH)(1.5)(NO(3))(0.5)center dot 0.6H(2)O to beta-Co(OH)(2) proceeds via an intermediate crystalline phase, which is thought to be an alpha-cobalt hydroxide with an expanded interlayer separation containing tetrahedrally coordinated Co(2+).
引用
收藏
页码:4450 / 4459
页数:10
相关论文
共 39 条
[1]   Probing in situ the nucleation and growth of gold nanoparticles by small-angle x-ray scattering [J].
Abecassis, Benjamin ;
Testard, Fabienne ;
Spalla, Olivier ;
Barboux, Philippe .
NANO LETTERS, 2007, 7 (06) :1723-1727
[2]  
Benson P., 1964, ELECTROCHIM ACTA, V9, P275
[3]   KINETIC MODEL FOR SOLID-STATE REACTIONS [J].
CARTER, RE .
JOURNAL OF CHEMICAL PHYSICS, 1961, 34 (06) :2010-&
[4]   The new materials processing beamline at the SRS Daresbury, MPW6.2 [J].
Cernik, RJ ;
Barnes, P ;
Bushnell-Wye, G ;
Dent, AJ ;
Diakun, GP ;
Flaherty, JV ;
Greaves, GN ;
Heeley, EL ;
Helsby, W ;
Jacques, SDM ;
Kay, J ;
Rayment, T ;
Ryan, A ;
Tang, CC ;
Terrill, NJ .
JOURNAL OF SYNCHROTRON RADIATION, 2004, 11 :163-170
[6]   DEVELOPMENT OF LARGE-VOLUME REACTION CELLS FOR KINETIC-STUDIES USING ENERGY-DISPERSIVE POWDER DIFFRACTION [J].
CLARK, SM ;
NIELD, A ;
RATHBONE, T ;
FLAHERTY, J ;
TANG, CC ;
EVANS, JSO ;
FRANCIS, RJ ;
OHARE, D .
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 1995, 97 (1-4) :98-101
[7]   THE CRYSTAL STRUCTURE OF CO2(OH)3CL [J].
DEWOLFF, PM .
ACTA CRYSTALLOGRAPHICA, 1953, 6 (04) :359-360
[8]   Synthesis, morphology, structure, and magnetic characterization of layered cobalt hydroxylsocyanates [J].
Du, Yi ;
O'Hare, Dermot .
INORGANIC CHEMISTRY, 2008, 47 (08) :3234-3242
[9]   Kinetic study of the intercalation of cobaltocene by layered metal dichalcogenides with time-resolved in situ X-ray powder diffraction [J].
Evans, JSO ;
Price, SJ ;
Wong, HV ;
O'Hare, D .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1998, 120 (42) :10837-10846
[10]   In situ small-angle and wide-angle X-ray scattering investigation on nucleation and crystal growth of nanosized zeolite A [J].
Fan, Wei ;
Ogura, Masaru ;
Sankar, Gopinathan ;
Okubo, Tatsuya .
CHEMISTRY OF MATERIALS, 2007, 19 (08) :1906-1917