Solvothermal Synthesis of Tetrahedrite: Speeding Up the Process of Thermoelectric Material Generation

摘要

Derivatives of synthetic tetrahedrite, Cu12Sb4S13, are receiving increasing attention in the thermoelectric community due to their exploitation of plentiful, relatively nontoxic elements, combined with a thermoelectric performance that rivals that of PbTe-based compounds. However, traditional synthetic methods require weeks of annealing at high temperatures (450-600 degrees C) and periodic regrinding of the samples. Here we report a solvothermal method to produce tetrahedrite that requires only 1 day of heating at a relatively low temperature (155 degrees C). This allows preparation of multiple samples at once and is potentially scalable. The solvothermal material described herein demonstrates a dimensionless figure of merit (ZT) vs temperature curve comparable to that of solid-state tetrahedrite, achieving the same ZT of 0.63 at similar to 720 K. As with the materials from solid-state synthesis, products from this rapid solvothermal synthesis can be improved by miming in a 1:1 molar ratio with the Zn-containing natural mineral, tennantite, to achieve 0.9 mol equiv of Zn. This leads to a 36% increase in ZT at similar to 720 K for solvothermal tetrahedrite, to 0.85.