Construction of selenide nanoparticle-anchored bimetallic MOF derivative NiFeSe@NiFe-MOF for application in high-performance supercapacitors

The design of nanostructured electrode materials and the tuning of their components is one of the effective ways to improve the electrochemical properties of the materials. Here, we employed a cost-effective hydrothermal synthesis method to successfully construct NiFeSe@NiFe-MOF electrode materials with nanocoral rod-like structures. The unique coral rod-like structure provides a larger specific surface area for electron storage, exposing more electrochemical reaction active sites on the electrode surface. Through DFT theoretical calculations we found that the metallic property of NiFeSe@NiFe-MOF-2 are greatly enhanced compared with NiFe-MOF, which can lead to higher conductivity and electron transfer efficiency of the selenized material. Moreover, the introduction of selenium enhances the adsorption capacity of the material for anions in alkaline solution, which makes the structure of the MOFs more stable and obtains better electrochemical reversibility making the electrochemical performance of the electrode material in all aspects. Compared with the NiFe-MOF material, NiFeSe@NiFe-MOF-2 has excellent capacitance retention up to 81.0 % at different current densities (1 A/g-10 A/g), and the stability of the cycle performance is greatly improved up to 84.0 %. The assembled device NiFeSe@NiFe-MOF-2 // AC has excellent multiplication performance up to 92.7 % and stable electrochemical cyclability up to 99.7 %. Moreover, the energy density is 61.0 Wh kg −1 at a power density of 5060.0 W kg −1 . The coral rod-like NiFeSe@NiFe-MOF composites synthesized in this experiment possessed excellent charge storage capacity and stability properties. These results indicate that the electrode materials developed in this paper have good application prospects in supercapacitors.