Investigation of the effects of heat treatment on the β-Ni(OH)2-β-NiOOH system using IR spectroscopy

The thermal characteristics of the β-Ni(OH)2-β-NiOOH system, in comparison with the thermal behaviour of pure β-Ni(OH)2, have been studied by IR spectroscopy in the 400–4000 cm−1 region. The IR spectra of samples treated at various temperatures between 20 and 300 °C, are presented together with some results obtained by thermogravimetric measurements. In addition to conventional IR analysis at ambient temperatures, an in-situ spectroscopic technique has also been used in the course of heat treatment in order to obtain information on the nature of the water adsorption observed on partly dehydrated hydroxides. Direct experimental verification of a previous assumption that the decomposition of the partly charged nickel hydroxide takes place in two almost independent steps is furnished by this IR method.