Antioxidation and thermoelectric properties of ZnO nanoparticles-coated β-FeSi2

Surface modification of β-FeSi2 by ZnO is verified to be an effective way to prevent oxidation and enhance thermoelectric (TE) properties of β-FeSi2. A simple approach is developed to fabricate well-covered, high-density and stable ZnO nanoparticles-coated β-FeSi2 (ZnO@β-FeSi2). First, β-FeSi2 (n-type Fe0.98Co0.02Si2) particles were prepared by mechanical alloying (MA) and pre-treated in sodium oleate solution to increase the polarity of the surface. Then, the pre-treated β-FeSi2 particles were successfully coated by ZnO nanoparticles during sol–gel process. Compared with that of uncoated β-FeSi2, antioxidation and thermoelectric performance of ZnO@β-FeSi2 materials is improved distinctly.