The Structure and Reactivity of Nickel Hydroxide

This paper examines the correlation between the structure and the reactivity of nickel hydroxide, using X-ray diffraction, DTA, IR spectroscopy, and gravimetry during dehydration. The degree of crystallization of β-nickel hydroxide depends on the preparation conditions of the hydroxide. Highly-crystallized β-nickel hydroxide has “free” hydroxyl groups, as is to be expected from its brucite structure. Poorly-crystallized β-hydroxide, however, has “hydrogen-bonded” hydroxyl groups, this finding is in disagreement with a previous result that “hydrogen-bonded” hydroxyl groups were found to exist only in α-form nickel hydroxide. The dehydration of the hydroxide is shown to take place in first-order kinetics with an activation energy which increases as the crystallization extends.