Metallurgical processing of copper secondary raw materials

Abstract

M. SOKIĆ i dr.

Synthesis and Characterization of N-Type CuGaS2 Nanoparticles and Films for Purpose of Photoelectrocatalytic Water Splitting

“…The TGA-MS small peak maximum at ∼106 °C for m/z = 18 (H 2 O) confirms the release of water molecules. The weight loss of ∼10 % between ∼280 °C and 500 °C may be attributed to the release of free sulfur oxide molecules 29,30 associated with slight oxidation of CuGaS 2 , and of water molecules and carbon oxide compounds related to the degradation of an organic compound (N-Methylimidazole). The TGA-MS peak between ∼280 °C and ∼500 °C for m/z = 64 (SO 2 , peak maximum at ∼402 °C), and the peak maximum at ∼467 °C for m/z = 44 (CO 2 ) and at ∼450 °C for m/z = 18 (H 2 O) support these interpretations.…”

“…When the temperature was maintained at 500 °C for 2 h, the TGA/DTG curves became flat and a slight weight loss of about 2.5 % occurred, probably due to the release of some sulfur oxide compounds. At temperatures above 500 °C, a weight loss of ∼10 % is mainly attributed to the release of SO 2 gas [29][30][31] (oxidation of sulfur atoms attached to copper and gallium in the CuGaS 2 structure and from elemental sulfur that didn't react during the synthesis of CuGaS 2 ) and to further degradation of N-Methylimidazole as suggested by the TGA-MS curves (SO 2 , CO 2 and H 2 O). To ensure sufficient crystallinity of the CuGaS 2 sample with the expected sulfur content, annealing treatment of as-synthesized material was done at 600 °C for 2 h under argon atmosphere, and 10 % excess sulfur was used.…”