Papers by Keyword: Ag₂S

Abstract: Thermoelectric generators (TEGs) are vital, reliable energy sources for both extreme environments such as deep space exploration and off-grid terrestrial applications, as well as emerging fields like wearable energy harvesters and biocompatible medical sensors. This study focuses on tin selenide (SnSe) combined with ductile silver sulfide (Ag₂S) to leverage their complementary properties: SnSe’s promising thermoelectric performance and mechanical robustness for homojunction TEGs, and Ag₂S’s exceptional ductility and thermal sensitivity ideal for flexible, biocompatible devices. Materials were synthesized using scalable powder metallurgy and spark plasma sintering (SPS) techniques, ensuring reproducibility and microstructural control tailored for these diverse applications. Our Bi-doped polycrystalline SnSe exhibits a unique polarity switching phenomenon and anisotropic behavior influenced by dopants (Bi, Ag, In), enabling optimized thermoelectric and mechanical properties that reduce interfacial stresses and enhance durability in harsh conditions. Meanwhile, the Ag₂S materials combine thermoelectric efficiency with fast thermal response and flexibility, suited for continuous physiological monitoring in wearable systems. The hybrid integration of SnSe homojunctions with flexible Ag₂S devices opens new possibilities for durable, efficient thermoelectric energy harvesting across wide temperature gradients in aerospace and biomedical fields.

Abstract: The worm-like morphology of silver sulfide (Ag₂S) was successfully prepared via hydrothermal reaction at 150°C by using silver nitrate (AgNO₃) and thioacetamide(CH₃CSNH₂) as both the sliver sources and sulfur sources, β-cyclodextrin as the template agent, and water as the solvent. The worm-like of Ag₂S are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), x-ray photoelectronspectroscopy (XPS), energy dispersivex-ray (EDX), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SEAD). Ultraviolet-visible spectra (UV-vis) and photoluminescencespectroscopy (PL) were used in an optical study of the products. The results showed that the existence of β-cyclodextrin is crucial to the formation of worm-like Ag₂S, and the optoelectronics test results showed that the sample have a broad absorption in ultraviolet and visible light region.

Abstract: The Ag-Ag₂S-PbS thin films were co-electrodeposited on indium-tin-oxide (ITO) coated glass substrates from aqueous solutions containing 0.01 M AgNO₃, 0.01 M Pb (NO₃)₂, 0.1 M Na₂S₂O₃, 0.02 M ethylenediaminetetraacetic acid disodium salt, and 0.5 M Na₂SO₄. X-ray diffraction (XRD), scanning electron microscopy (SEM), and cyclic voltammetry (CV) were used to investigate the Ag-Ag₂S-PbS thin films. The X-ray diffraction analysis demonstrated the presence of cubic structure of metallic silver, acanthite Ag₂S, and cubic PbS, which is consistent with the CV analysis. The effect of different Ag⁺/Pb²⁺ ratios on the morphology and composition of the Ag-Ag₂S-PbS thin films were also studied.

Abstract: We conducted light irradiation experiments in air to clarify influence of atmosphere on the operation of a photo-assisted atomic switch. In air, Pt-Ag₂S/Ag nanogap electrodes with a PTCDI thin layer in their nanogaps showed current fluctuations with an applied bias of from 1.5 V to 6 V regardless of the bias polarity and with or without light irradiation. This is in contrast to the fact that only two things cause an increase in current that result in the formation of a silver bridge and switching behavior under vacuum, namely, light irradiation and the application of positive bias to the Ag₂S/Ag electrode [. In addition, photocurrent caused by irradiating a PTCDI thin layer was found to be sensitive to air and to N₂. These results indicate that moisture or other gas molecules in air and in N₂ have an influence on the photo-assisted atomic switching behavior.

Abstract: ZnS thin films were deposited on indium–tin-oxide (ITO) coated glass substrates by a chemical bath deposition method. Then the ZnS/ITO slides were immersed in the solution containing 6 mM phosphate buffer solution (pH 7.4), sodium polyacrylate (0.01% w/w), and 0.24 mM AgNO₃ at 37°C for 3 h to growth Ag2S films on the surface of ZnS/ITO slides. The absorption band of Ag₂S/ZnS/ITO slide displays a considerably blue-shifted. The X-ray diffraction analysis demonstrated the presence of acanthite Ag₂S on the surface of ZnS/ITO slides, which is consistent with the cyclic voltammetic data.

Abstract: Ag₂S nanorods and nonoparticles have been successfully prepared using chemical method. Silver nitrate with molar concentration of 0.1 M and thiourea with different molar concentration were used as a source of Ag⁺⁺ and S⁺⁺ ions, respectively. The pH of solution was in range of 10-11. Scanning electron microscopy (SEM) image showed that the nanorods length and diameter were 2.5-3 μm and 300-400 nm, respectively. X-ray diffraction results showed a monoclinic α-Ag₂S phase was obtained. The atomic ratio of silver and sulphur were found using energy dispersive spectroscopy (EDS) and it was 62.39% and 37.61%, respectively.

Abstract: We herein report the feasibility of polymer-inorganic solid-state reaction route for simultaneous in situ generation of Ag & Ag2S nanostructures in polymer network wherein an engineering thermoplastic, polyphenylene sulphide (PPS), itself acts as a chalcogen source as well as a stabilizing matrix for the resultant nanoproducts. Typical solid-state reaction was accomplished by simply heating the physical admixture of the two reactants i.e. AgNO3 and PPS by varying molar ratios mainly 1:1, 1:5, 1:15, 1:20, at the crystalline melting temperature (285 °C) of PPS. The synthesized nanoparticles were characterized by various physico-chemical techniques like X-ray Diffractometry, Scanning Electron Microscopy equipped with EDAX, Transmission Electron Microscopy and UV-Visible spectroscopy. The prima facie observations suggest the effective formation and subsequent entrapment of mainly nanocrystalline metallic silver (fcc) in PPS matrix for all the molar ratios chosen for the reaction. Additionally, simultaneous occurrence of nanocrystalline Ag2S (monoclinic phase) is also noticed in case of heated admixture of AgNO3: PPS with equimolar ratio. The TEM analysis reveals nanoscale polydispersity (5nm to 70nm) and prevalence of mainly spherical morphological features in all the cases with occasional indications of triangular and hexagonal morphological features depending upon the reaction molar ratio.