Controllable Synthesis of Bi₂Te₃ Intermetallic Compounds with Hierarchical Nanostructures via Electrochemical Deposition Route

Bismuth-tellurium intermetallic compounds have proven to be one of the best thermoelectric materials with the highest figure of merit and have proven to be very useful for devices operating at room temperature. Here, we report that the Bi 2 Te 3 intermetallic compounds with novel hierarchical nanostructures can be successfully synthesized by an electrochemical deposition route, which presents a simple, quick, and economical method for the preparation of Bi 2 Te 3 intermetallic compounds and the controllable growth of hierarchical nanostructures. Cyclic voltammetry was used to study the electrochemical reactions relevant to the growth of Bi 2 Te 3 intermetallic compounds, and the electrochemical formation process of Bi 2 Te 3 intermetallic compounds was also investigated in this paper. The synthetic parameters in this research allowed various structural manipulations for Bi 2 Te 3 intermetallic compounds, and the formation mechanisms of Bi 2 Te 3 intermetallic compounds with hierarchical nanostructures were proposed. The concentration ratio of Bi(NO 3 ) 3 to Na 2 TeO 3 was a key factor that affected the morphologies and structures of Bi 2 Te 3 intermetallic compounds. These prepared novel hierarchical Bi 2 Te 3 nanostructures are desired low dimensional thermoelectric building blocks for possibly achieving a high thermoelectric figure of merit.