Influence of precursor concentration, surfactant and temperature on the hydrothermal synthesis of CuS: structural, thermal and optical properties

Abstract

Herein we demonstrate the synthesis and formation mechanism of copper sulfide (CuS and Cu 2 S) by a simple hydrothermal process in the temperature range of 150-250 1C. The molar concentration ratio of copper nitrate to sodium thiosulfate precursor, and the reaction temperature play important roles in determining the morphology and composition of the product. At a higher thiosulfate concentration, elemental sulfur precipitates out along with CuS. However, the elemental sulfur is degraded with increasing of the reaction temperature. The morphology of the as-synthesized product is primarily a sphere-like agglomeration of either nanoparticles and/or nanoplates. The surfactant is found to be indispensable for obtaining dispersed nanocrystals. The stability of CuS and the formation of different copper compounds at higher temperature are studied in detail using thermal analysis and X-ray diffraction (XRD). The phase pure CuS is found to be completely converted to CuO upon calcining in air at 800 1C. However, the in situ high temperature XRD measurements in a vacuum show complete conversion of CuS to Cu 2 S at 600 1C without any intermediate phases. The optical bandgap of the as-synthesized CuS nanocrystals is measured to be B1.7 eV.

Enhancement of Hydrogen Productions by Accelerating Electron-Transfers of Sulfur Defects in the CuS@CuGaS2 Heterojunction Photocatalysts

“…On the other hand, the peaks at 31.74 • and 46.11 • correspond to Cu 2 S (JCPDS card no. 00-053-0522) of cubic crystal structure, meaning that the two structures are finely mixed [21]. The XRD patterns of the CuGaS 2 nanoparticle showed a CuGaS 2 peak with a tetragonal crystal structure (I-42d space group, JCPDS card no.…”

Axial Composition Gradients and Phase Segregation Regulate the Aspect Ratio of Cu2ZnSnS4 Nanorods

“…47,48 In our case, the fact that the CZTS aspect ratio is so dependent on Cu loading, along with the aforementioned axial composition gradient, strongly indicates that the Cu precursor is more reactive than the Zn (and Sn) precursors. Selectivity for anisotropic growth and formation of composition gradients are closely related phenomena that result from sequential nucleation events.…”

Enhancement of electrical conductivity of carbon nanotube fibers by copper sulfide plating

“…The results of the thermal analysis are presented in Figure 3 where PEIcoated CNT yarns start losing weight earlier than untreated CNT yarns, probably as a result of the presence of PEI. Also, the CuS-plated on the CNT yarns is known to decrease in weight as CuS is converted into Cu 2 S at the near 380 o C [33]. CuS also reacts with oxygen to form CuSO 4 , which contributes to weight gain.…”