Catalytic Properties of Yttrium Bromide Hydrolysis Products

Abstract

The effect of hydrolysis time, final pH of synthesis, and hydrothermal treatment on the formation of yttrium oxyhydroxides obtained by alkaline hydrolysis of yttrium bromide was studied. Hydrolysis was carried out at different duration of the hydrolytic agent addition: 5 minutes, 1 hours and 24 hours, as well as at different final pH values were checked: 8, 9 and 10. Methods for characterization of resulting materials were: thermogravimetry combined with differential scanning calorimetry and mass spectrometry of gaseous products of thermolysis, X-ray diffraction, high-resolution scanning electron microscopy with EDX elemental analysis. In addition, a photocatalytic activity of the obtained samples was evaluated in the decomposition reaction of methylene blue under the UV radiation. It is established that the hydrolysis of yttrium bromide involves the capture of a significant amount of impurities of bromide and carbonate ions, which are present in the structure of the samples. The physical and chemical characteristics of yttrium bromide hydrolysis products depend on both the pH value and hydrolysis duration, as well as on hydrothermal treatment. The latter significantly increases the crystallinity of the samples and their photocatalytic performance in destruction reaction of methylene blue.