Jahangiri Soran, Mosey Nicholas J
Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, ON K7M 0A9, Canada.
Phys Chem Chem Phys. 2018 Apr 25;20(16):11444-11453. doi: 10.1039/c8cp00070k.
The structure and properties of α-Ni(OH)2 containing water and nitrate have been investigated computationally. The adsorption of water molecules on the Ni(OH)2 surface is also investigated to provide insight into the nature of the water-Ni(OH)2 interactions. The spectroscopic and dynamical behaviour of the intercalated species has been characterized and used to explain experimental findings reported for this material. The results presented here indicate that the water molecules interact non-covalently with Ni(OH)2, with a binding energy that is comparable in magnitude with that of the water dimer hydrogen bond. The presence of the intercalated species increases the distance between the Ni(OH)2 layers such that the interlayer interactions are negligible. The weakening of the interlayer interactions facilitates the horizontal displacement of the layers relative to one another, providing a possible origin for stacking faults observed in α-Ni(OH)2. Comparison of the vibrational frequencies calculated here with the experimental spectra confirms that α-Ni(OH)2 containing only water molecules can be synthesized. The structures of the water molecules intercalated in α-Ni(OH)2 were found to be analogous to those absorbed in γ-NiOOH, while the water-layer interactions are stronger in γ-NiOOH. The results presented here characterize the structure and interactions of water intercalated in nickel hydroxides and also provide insights into the effects of intercalated water on the properties of layered metal hydroxides.
通过计算研究了含水和硝酸盐的α-Ni(OH)₂的结构与性质。还研究了水分子在Ni(OH)₂表面的吸附情况，以深入了解水与Ni(OH)₂之间相互作用的本质。对插层物种的光谱和动力学行为进行了表征，并用于解释针对该材料报道的实验结果。此处给出的结果表明，水分子与Ni(OH)₂以非共价方式相互作用，其结合能在大小上与水二聚体氢键的结合能相当。插层物种的存在增加了Ni(OH)₂层之间的距离，使得层间相互作用可以忽略不计。层间相互作用的减弱促进了各层相对于彼此的水平位移，这为在α-Ni(OH)₂中观察到的堆垛层错提供了一种可能的成因。将此处计算得到的振动频率与实验光谱进行比较，证实了仅含水分子的α-Ni(OH)₂是可以合成的。发现插层在α-Ni(OH)₂中的水分子结构与吸附在γ-NiOOH中的水分子结构类似，而在γ-NiOOH中水分子与层之间的相互作用更强。此处给出的结果表征了插层在氢氧化镍中的水的结构和相互作用，也为插层水对层状金属氢氧化物性质的影响提供了见解。
