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

► The β-FeSi2 particles are well coated by ZnO nanoparticles. ► This method is simple and effective. β-FeSi2 particles are pre-treated in sodium oleate solution to increase the polarity of the surface; and then, the pretreated β-FeSi2 particles are coated by ZnO nanoparticles during sol-gel process. ► The antioxidation and thermoelectric properties of β-FeSi2 are improved distinctly due to the coating.