Facile synthesis of flake-like FeSe2 particles in open-air conditions

FeSe2 particles were facilely synthesized through a simple solvothermal reduction reaction in air. By using iron nitrate and selenide as raw materials, and oleylamine as solvent, 96% yield of the FeSe2 particles with flake-like structures was obtained. Different morphologies of the FeSe2 particles, such as globular, flocculent, and flake structures, were achieved by changing the reaction temperatures. Meanwhile, the probable growth mechanism and fabrication process of the products were proposed. The Raman spectra of the FeSe2 samples showed the characteristic peaks of Se-Se active modes. The optical properties demonstrated that the products had a broad optical absorption in NIR, which was related to the corresponding microstructure.