Room-temperature chemical synthesis of silver telluride nanowires

Abstract

We have developed a room-temperature solution-phase route for the preparation of one-dimensional silver telluride nanowires (Ag₂Te NWs). The Ag₂Te NWs of 600 nm length and 20 nm diameter were synthesized by the reaction of tellurium nanowires (Te NWs) with silver nitrate (AgNO₃) in water. We propose that Te NWs act as the template and the reducing agent simultaneously, enabling the formation of polycrystalline Ag₂Te NWs. Various microscopic and spectroscopic tools, such as HRTEM, SEM, EDAX, XRD, DSC, XPS, and Raman, were used for the characterization of Ag₂Te NWs. The phase transition corresponding to the structural transition from the low-temperature monoclinic phase to the high-temperature face-centered cubic phase occurs at 417.7 K. We studied the electrical resistance and investigated the influence of temperature on the thermal emf. The Seebeck coefficient showed a maximum of ~142 μV K^-1, a value much higher than that of the bulk material and thin films (65-130 μV K^-1). A surface-enhanced Raman scattering investigation of dispersed Ag₂Te NWs showed them to be sensitive up to 10^-7 M crystal violet. The monodispersity and the homogeneity of the NWs through a simple solution-phase protocol would pave the way for further studies and applications.