Development of Crystalline Cu2S Nanowires via a Direct Synthesis Process and Its Potential Applications

Abstract

Large-scale and uniform copper(I) sulfide (Cu2S) nanowires have been successfully synthesized via a cheap, fast, easily handled, and environmentally friendly approach. In addition to the reductive properties of the biomolecule-assisted method, they also have a strong shape- or size-directing functionality in the reaction process. The field-emission properties of the Cu2S nanowires in a vacuum were studied by the Folwer–Nordheim (F–N) theory. The Cu2S nanowires have a low turn-on field at 1.19 V/μm and a high enhancement factor (β) of 19,381. The photocatalytic degradation of Cu2S nanowires was investigated by the change in the concentrations of rhodamine B (RhB) under UV illumination. These outstanding results of Cu2S nanowires indicate that they will be developed as good candidates as electron field emitters and chemical photocatalysts in future nanoelectronic devices.

Ag Nanoparticle-Decorated Cu2S Nanosheets for Surface Enhanced Raman Spectroscopy Detection and Photocatalytic Applications

“…Figure 3c demonstrates that the efficiency (η) of the RhB photodegradation using the Ag/Cu 2 S nanosheets and undecorated Cu 2 S nanosheets was 90.3 and 31.3, respectively. Interestingly, the photocatalytic activity of the Ag/Cu 2 S nanosheets surpassed that of the Cu 2 S nanowires in our previous work [8]. Figure 3d According to Figure 2c, Ag/Cu 2 S nanosheets prepared at 30 • C possess better SERS performance than those obtained at 20 and 40 • C, which can be attributed to the uniform distribution of the Ag NPs on the edge of the Cu 2 S nanosheets at 30 • C. As shown in Figure 2d, SERS intensity was accordingly decreased, while the concentration of the R6G dye molecule decreased.…”

“…Figure 3c demonstrates that the efficiency (η) of the RhB photodegradation using the Ag/Cu 2 S nanosheets and undecorated Cu 2 S nanosheets was 90.3 and 31.3, respectively. Interestingly, the photocatalytic activity of the Ag/Cu 2 S nanosheets surpassed that of the Cu 2 S nanowires in our previous work [8]. Figure 3d shows that the photocatalytic degradation of the RhB dye followed a pseudo-first-order reaction according to the Langmuir-Hinshelwood mechanism [30,31], applying Equation (1):…”

“…Therefore, in order to get insight into the electronic state in the Ag/Cu 2 S nanosheets, XPS analysis was carried out and the results are shown in Figure 4. Figure 4a [8].…”

“…Among various metal chalcogenide semiconductors, copper(I) sulfide (Cu 2 S) has an energy bandgap of 1.21 eV that could be applied in optoelectronics and photocatalysis [4][5][6]. Cu 2 S nanomaterials are quite attractive because many of the proposed fabrication methods are inexpensive and lend themselves well to mass production [4][5][6][7][8]. Cu 2 S nanostructures, including nanocrystals, nanowires, and nanosheets, have aided in developing highly efficient photocatalysts for the environmental photocatalytic degradation of organic pollutants [6][7][8].…”

“…All diffraction peaks could be ascribed to the orthorhombic crystal of Cu 2 S (JCPDS No. 23-0961) with lattice constants of a = 1.35 nm, b = 2.73 nm, and c = 1.19 nm[8], apart from the three additional peaks (2θ = 27.52 • , 43.32 • , and 50.45 • ) corresponding to the Cu foil. Even though the peak intensity of the Ag NPs of the Ag/Cu 2 S nanosheets was lower than that of the Cu 2 S structures in the XRD patterns, the appearance of the peak of the Ag (111) diffraction plane is clear in Figure1f, indicating that Ag NPs were successfully embedded in the interface of the Cu 2 S nanosheets.…”