Preparation of Bi2Te3 thermoelectric powders by applying the recycled TeO2 to wet chemical process

Extraction of TeO2 from the byproduct solution generated during the copper smelting process and application of the extracted TeO2 to the preparation of Bi–Te alloy thermoelectric materials were performed via a wet chemical processes. In the wet chemical process, powder purifying steps were optimized by adjusting the pH of NaOH solvent to dissolve the initially extracted Te compounds and by washing the finally extracted powders. TeO2 powders used in preparing the Bi–Te alloy thermoelectric materials could be successfully extracted from the byproduct solution by the optimized wet chemical process. Powders synthesized by applying the commercial and the extracted TeO2 powders to the wet chemical process showed identical crystal structures of Bi2Te3 and a mean particle size of ∼3 μm. Thus, it is believed that the recycled TeO2 powders will be very useful in the preparation of Bi–Te alloy thermoelectric materials.