Thermoelectric Characteristics of Flexible Reduced Graphene Oxide/Silver Selenide Nanowire Composites Prepared by a Facile Vacuum Filtration Process

The reduced graphene oxide/silver selenide nanowire (rGO/Ag2Se NW) composite powders were fabricated via a wet chemical approach, and then flexible rGO/Ag2Se NW composite film was prepared by a facile vacuum filtration method combined with cold-pressing treatment. A highest power factor of 228.88 μWm-1K-2 was achieved at 340 K for the cold-pressed rGO/Ag2Se NW composite film with 0.01 wt% rGO. The rGO/Ag2Se NW composite film revealed superior flexibility as the power factor retained 94.62% after bending for 500 times at a bending radius of 4 mm, which might be due to the interwoven network structures of Ag2Se NWs and pliability of rGO as well as nylon membrane. These results demonstrated the GO/Ag2Se NW composite film has a potential for preparation of flexible thermoelectric devices.

Bio-inspired silver selenide nano-chalcogens using aqueous extract of Melilotus officinalis with biological activities

For the first time, an aqueous extract of Melilotus officinalis was used to synthesize bimetallic silver selenide chalcogenide nanostructures (Ag2Se-NCs). The formation of NCs was confirmed and characterized by UV–visible and FTIR spectroscopy, SEM and TEM imaging, XRD and EDX crystallography, zeta potential (ZP) and size distribution (DLS). The bioactivities of biosynthesized Ag2Se-NCs, such as antibacterial, antibiofilm, antioxidant and cytotoxicity potentials, were then examined. Bio-based Ag2Se-NCs were successfully synthesized with mostly spherical shape in the size range of 20–40 nm. Additionally, the MIC and MBC values of Ag2Se-NCs against β-lactam-resistant Pseudomonas aeruginosa (ATCC 27853) were 3.12 and 50 µg/ml, respectively. The DPPH scavenging potential of Ag2Se-NCs in terms of IC50 was estimated to be 58.52. Green-synthesized Ag2Se-NCs have been shown to have promising benefits and could be used for biomedical applications. Although the findings indicate promising bioactivity of Ag2Se-NCs synthesized by M. officinalis extract (MO), more studies are required to clarify the comprehensive mechanistic biological activities.

Superionic phase transition in individual silver selenide nanowires

The superionic phase transition temperature in Ag2Se nanowires is diameter dependent and suppressed to below 100 °C. An increase in charge carrier density accompanied by a decrease in mobility was observed across the superionic phase transition.

High zT in Electrodeposited Silver Selenide Films: From Pourbaix Diagram to a Flexible Thermoelectric Module

In the last years, to explore new thermoelectric materials with low-toxicity, earth-abundant, and high-efficiency has become essential. Following this trend, sustainable, easily scalable, and cost-effective fabrication methods, such as electrochemical...

Sugar-Mediated Green Synthesis of Silver Selenide Semiconductor Nanocrystals under Ultrasound Irradiation

Silver selenide (Ag2Se) is a promising nanomaterial due to its outstanding optoelectronic properties and countless bio-applications. To the best of our knowledge, we report, for the first time, a simple and easy method for the ultrasound-assisted synthesis of Ag2Se nanoparticles (NPs) by mixing aqueous solutions of silver nitrate (AgNO3) and selenous acid (H2SeO3) that act as Ag and Se sources, respectively, in the presence of dissolved fructose and starch that act as reducing and stabilizing agents, respectively. The concentrations of mono- and polysaccharides were screened to determine their effect on the size, shape and colloidal stability of the as-synthesized Ag2Se NPs which, in turn, impact the optical properties of these NPs. The morphology of the as-synthesized Ag2Se NPs was characterized by transmission electron microscopy (TEM) and both α- and β-phases of Ag2Se were determined by X-ray diffraction (XRD). The optical properties of Ag2Se were studied using UV–Vis spectroscopy and its elemental composition was determined non-destructively using scanning electron microscopy–energy-dispersive spectroscopy (SEM–EDS). The biological activity of the Ag2Se NPs was assessed using cytotoxic and bactericidal approaches. Our findings pave the way to the cost-effective, fast and scalable production of valuable Ag2Se NPs that may be utilized in numerous fields.