Observation of staging during intercalation in layered alpha-cobalt hydroxides: a synthetic and kinetic study.
Observation of staging during intercalation in layered alpha-cobalt hydroxides: a synthetic and kinetic study.
复制标题
层状α-氢氧化钴插层期间的观察：合成和动力学研究。
作者：
Yi Du;D. O′Hare
研究了层状α-氢氧化钴Co(OH)(1.75)(DDS)(0.25).0.6H(2)O(1)和Co(OH)(1.7)Cl(0.3).0.4H(2)O(3)与碳酸盐的阴离子交换反应。对于3，反应通过CO(3)(2-)将层间氯(-)阴离子完全置换得到Co(OH)(1.7)(CO(3))(0.15).0.6H(2)O(4)。值得注意的是，对于1，我们只观察到每隔一层DDS(-)的离子交换，得到第二阶段的嵌入Co(OH)(1.75)(DDS)(0.07)(CO(3))(0.09).0.5H(2)O(2)。用时间分辨原位能量色散X射线衍射仪和小/广角X射线散射仪研究了这些过程的动力学。在这两种情况下，反应级数(N)均符合二维扩散控制模型。3和4都是磁性有序的，直流和交流磁化率测量被用来探索它们的3D亚铁磁性基态。
The anion-exchange reaction of the layered alpha-cobalt hydroxides Co(OH)(1.75)(DDS)(0.25).0.6H(2)O (1) and Co(OH)(1.7)Cl(0.3).0.4H(2)O (3) with carbonate has been investigated. For 3 the reaction proceeds by complete displacement of the interlayer Cl(-) anions by CO(3)(2-) to give Co(OH)(1.7)(CO(3))(0.15).0.6H(2)O (4). Remarkably for 1 we only observe ion-exchange of the DDS(-) from every other layer to give the second stage intercalate Co(OH)(1.75)(DDS)(0.07)(CO(3))(0.09).0.5H(2)O (2). The kinetics of these processes have been investigated using time-resolved in situ energy dispersive XRD and small/wide-angle X-ray scattering. In both cases the reaction order (n) was found to be consistent with a two-dimensional diffusion controlled model. Both 3 and 4 are magnetically ordered, and dc and ac magnetic susceptibility measurements have been used to explore their 3D ferrimagnetically ordered ground states.