Decomposition of the sulfates of copper, iron II/, iron III/, nickel, and zinc: XPS, SEM, DRIFTS, XRD, and TGA study

The bulk and surface characteristics during decomposition of the transition metal sulfates of copper, iron II., iron III., nickel, and zinc are investigated utilizing various spectroscopic techniques. An oxidized form of sulfur was detected on the surface during decomposition of all metal sulfate samples, except zinc sulfate. Surface characteristics were not necessarily representative of the bulk characteristics. Oxy-sulfate was observed with copper sulfate only. Lower decomposition temperatures were observed in vacuum as compared to those at atmospheric pressure. Uniform sulfur distribution was observed across sample cross sections. Analysis consisted of Scanning electron microscopyrX-ray microanalysis, X-ray photoelectron spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy, thermogravimetric analysis, and X-ray diffraction. q1999 Published by Elsevier Science B.V. All rights reserved