Ag–Ag2S–CdS nanostructures: formation, physical characteristics and role in methylene blue removal

• Published in: Journal of materials science. Materials in electronics 2024-09, Vol.35 (27), p.1799, Article 1799
• Main Authors: Gahramanli, Lala R., Muradov, Mustafa B., Kim, Jiseok, Eyvazova, Goncha M., Gasimov, Eldar K., Rzayev, Fuad H., La Pietra, Matteo, Gomez, Cristian Vacacela, Bellucci, Stefano
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Core-shell structure; Damping; Degradation; Electron transitions; Fourier transforms; Infrared spectroscopy; Ion exchange; Materials Science; Methylene blue; Microscopy; Nanowires; Optical and Electronic Materials; Photoluminescence; Physical properties; Silver; Spectrum analysis; Surface defects; Surface plasmon resonance; Synthesis; Transmission electron microscopy
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-024-13539-8

In this study, pure silver nanowires (Ag NWs) were initially synthesized using the polyol method. Subsequently, Ag–Ag 2 S NWs were synthesized through hybridization at two different concentrations (0.01 and 0.001 M). The final product, Ag–Ag 2 S–CdS NWs with a one-dimensional (1D) unit structure, was obtained via an ion-exchange method using a Cd 2+ cation source. To characterize these NWs, various techniques were employed: X-ray Diffraction (XRD), Ultraviolet–Visible (UV–Vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Photoluminescence (PL) spectroscopy, and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray Spectroscopy (EDX) and, Transmission Electron Microscopy (TEM). The results confirmed the successful formation of the intended compounds through the synthesis process. TEM images verified the 1D core–shell structure of the NWs, with dimensions as follows: pure Ag NWs [D = 0.001 µm (1 nm)], Ag–Ag 2 S NWs (D = 0.52 µm), and Ag–Ag 2 S–CdS NWs (D = 0.61 µm). The PL spectrum revealed that pure Ag NWs exhibit high conductivity and surface plasmon resonance in the 400–500 nm range. The incorporation of semiconducting Ag 2 S altered the electron transition dynamics in the Ag–Ag 2 S system, attributed to surface defects in Ag 2 S. Additionally, in the presence of CdS, a decrease in intensity around 441 nm and spectrum broadening were observed, primarily due to Interband Damping. The degradation efficiency of Methylene Blue (MB) dye using Ag–Ag 2 S–CdS NWs as potential nanocatalysts was tested over various time intervals (60, 120, 180, 240, and 300 min) in three different environments (pH = 3, pH = 6, and pH = 10). The optimal degradation occurred in an acidic environment (pH = 3), achieving 97.9% efficiency at 300 min. The degradation kinetics were determined to be 0.0085 (60–120 min) and 0.0016 (120–300 min) in the acidic environment, 0.0029 in the neutral environment, and 0.0071 (60–180 min) and 0.001 (180–300 min) in the alkaline environment.