Synthesis and Characterization of nanoscale Bi2Te3, Sb2Te3, PbTe and Ag2Te powders: activated Metals and soluble Tellurium sources as synthetic Tools

Abstract

Binary tellurides such as PbTe or Bi₂Te₃ represent one of the fundamental classes of thermoelectrics. Thus, the development of new routes for the preparation of these compounds as nanoscale powders is an important challenge. In this context, we investigated the use of activated metals and soluble tellurium sources such as diphenyltelluride or the tellurolates of hard transition metal cations as versatile tool box system for the synthesis of these powders. Using solvochemically activated lead, bismuth or antimony, their respective tellurides PbTe, Bi₂Te₃ and Sb₂ Te₃ could be obtained in a reaction with Ph₂Te₂ following the same experimental protocol in all cases. The preparation of an Ag₂Te nanopowder required a different synthetic approach as elemental silver does not react with Ph ₂Te₂. Following the principle of hard and soft acids and bases, silver acetate and zinc tellurolate Zn(TePh)₂middotTMEDA [Jun, Y, 2001] were reacted to form nanoparticles of Ag₂Te from intermediately formed silver tellurolate