FeSe_(2)/CoSe_(2)@C纳米复合材料的制备及电催化析氢性能

Preparation of FeSe_(2)/CoSe_(2)@C nanocomposite and electrocatalytic hydrogen evolution performance

采用等离子体直流电弧法与气相硒化法相结合制备了FeSe_(2)/CoSe_(2)@C纳米复合材料。利用X射线衍射、透射电镜、X射线光电子能谱、电化学工作站等对样品的物相、形貌、表面组成以及电催化析氢性能进行了详细研究。研究表明,FeSe_(2)/CoSe_(2)@C纳米复合材料呈现出明显的核壳结构,与未经硒化处理的FeCo@C纳米颗粒相比,经过硒化处理的样品表现出更加优异的电催化析氢性能。FeSe_(2)/CoSe_(2)核具有大量的活性位点促进了H2的生成;C壳层具有优异的导电性,提升了电子快速传输的能力,这种核壳间的协同作用进一步提高了电催化析氢的性能。通过进一步优化FeCo@C和Se粉的用量,发现催化剂在电流密度为10 mA·cm-2处的过电位为159 mV,同时,FeSe_(2)/CoSe_(2)@C纳米复合材料在酸性条件下展现出较为优异的电化学稳定性。

FeSe_(2)/CoSe_(2)@C nanocomposites were prepared by the plasma direct current arc method combined with gas phase selenization method. The phase, morphology, surface composition and electrocatalytic hydrogen evolution performance of the samples were studied in detail using X-ray diffraction(XRD), transmission electron microscopy(TEM), X-ray photoelectron spectroscopy(XPS) and electrochemical workstation. Studies have shown that FeSe_(2)/CoSe_(2)@C nanocomposites exhibit obvious core-shell structure. Compared with FeCo@C nanoparticles, the FeSe_(2)/CoSe_(2)@C nanocomposites show more excellent electrocatalytic hydrogen evolution performance. The FeSe_(2)/CoSe_(2)core has a large number of active sites to promote the generation of H2;while the C shell layer has excellent electrical conductivity, which improves the ability of rapid electron transport. This synergy between the core and shell further improves the performance of electrocatalytic hydrogen evolution. By further optimizing the amount of FeCo@C and Se powder, it is found that the overpotential of the catalyst at a current density of 10 mA·cm-2is 159 mV. At the same time, FeSe_(2)/CoSe_(2)@C nanocomposites exhibit excellent electrochemical stability under acidic conditions.