Preparation and optimization of thermoelectric properties of Bi 2Te 3 based alloys using the waste particles as raw materials from the cutting process of the zone melting crystal rods

摘要

AbstractThe p-type Bi2Te3alloys were prepared using the waste particles from the cutting process of the zone melting crystal rods as the main raw materials by impurity removal process including washing, carbon monoxide reduction and vacuum metallurgical process. The thermoelectric properties of the Bi2Te3based bulk materials were optimized by component adjustment, second smelting and resistance pressing sintering (RPS) process. All evidences confirmed that most of impurities from the line cutting process and the oxidation such as Sb2O3, Bi2O3and Bi2Te4O11could be removed by carbon monoxide reduction and vacuum metallurgical process adopted in this work, and the recycling yield was higher than 97%. Appropriate component adjustment treatment was used to optimize the carrier content and corresponding thermoelectric properties. Lastly, a Bi0.36Sb1.64Te3bulk was obtained and its power factor (PF) could reach 4.24?mW?m?1?K?2at 300?K and the averagePFvalue was over 3.2?mW?m?1?K?2from 300?K to 470?K, which was equivalent with the thermoelectric performance of the zone melting products from high purity elements Bi, Te and Sb. It was worth mentioning that the recovery process introduced here was a simple, low-cost, high recovery rate and green recycling technology.Graphical abstractDisplay OmittedHighlights?Waste particles of cooling rod were recycled by CO reduction and vacuum metallurgy.?The recycling technology is accordance with the principle of 3-R.?The recycling yield of the Bi2Te3based waste was over 97%.?ThePFvalue of Bi0.36Sb1.64Te3bulk could reach 4.24?mW?m?1?K?2at 300?K.?The averagePFof Bi0.36Sb1.64Te3