Hydrothermal Synthesis And Properties Of FeSe₂ Materials

Iron selenides?FeSe_x?have attracted a great interest due to their applications in the fields of superconductors,electrochemistry and optical.FeSe₂ are gradually focused due to its stable orthorhombic structure leading to potential applicatons as electrode materials and photocatalytic materials.In this article,octahedral FeSe₂ materials were synthesized via hydrothermal method.FeCl₂·4H₂O was iron raw material,Se powder and Na₂SeO₃ were Se materials separately.the characterization of XRD and SEM showed that pure orthorhombic FeSe₂ could synthesised on the control of factor and the ratio of raw materials in reaction.Meanwhile,the pure FeSe₂ exhibited excellent photocatalytic performance and characters of electrode materials.?1?The proper reaction conditions were obtained by controlling the hydrothermal reaction temperature and time: temperature was at 180? and the reaction time was 24 hours.The influence conducted by the ratio of Fe source and Se source was observed,XRD figure showed that the pure FeSe₂ was obtained as the ratio of Fe and Se was 1:2,on the other hand,the figure of SEM showed the shape of precipitate was octahedron;the formation mechanism was discussed.?2?The effects of the concentration of reactants and the formation of organic solvents on the formation of FeSe₂ were investigated under the optimum reaction conditions.The results showed that the organic solvent had not obvious effect on the experimental results,which ensured the simplicity of the synthesis process.Raman test showed that the product exhibited Se-Se tensile vibration,rotational vibration peaks and Fe-Se vibrational peaks.The results of photocatalytic test showed that the prepared FeSe₂ had better photocatalytic degradation effect on rhodamine B,and the degradation efficiency of FeSe₂ was 0.5mol / L,which was slightly lower than that of P25.?3?The products of Se powder and sodium selenite?Na₂SeO₃?as Se sources were obtained respectively,and their characterization and photoelectric properties were tested.XRD results showed that the prepared samples were pure FeSe₂.SEM showed that FeSe₂ prepared with Se powder which was as Se source was octahedron and FeSe₂ prepared with Na₂SeO₃ as Se source was a mixture of octahedral and rod.In the photocatalytic degradation of rhodamine B,the degradation rate of FeSe₂ prepared by Se powder which was as Se source was higher,closing to the degradation of the P25.Electrochemical tests showed that FeSe₂ were of potential applications as electrode material.