Metal organic frameworks derived hierarchical hollow Ni0.85Se|P composites for high-performance hybrid supercapacitor and efficient hydrogen evolution

Hollow nano-/micromaterials with tunable shell architectures and compositions are becoming increasingly important and attractive for electrochemical energy conversion and storage. Here, we report carbon-incorporated mixed anionic nickel phosphorus-selenium (Ni 0.85 Se|P) hollow yolk-shell microspheres synthesized by simultaneous selenization and phosphatization of Ni-based metal organic framework (Ni-MOF). Our experimental results indicated that P-doping reduces the synthesis temperature of the system and enhances the crystallinity of Ni 0.85 Se. As a result, this unique structure (Ni 0.85 Se|P) with better crystallinity and higher Ni 2+ /Ni 3+ ratio shows outstanding specific capacity of 506 C g −1 at 1 A g −1 . And the assembled Ni 0.85 Se|P//AC hybrid supercapacitor shows high power density of 20.7 Wh kg −1 at energy density of 798.7 W kg −1 . Meanwhile, Ni 0.85 Se|P exhibits smaller Tafel slope of 90 mV dec −1 and lower onset overpotential of 179 mV versus reversible hydrogen electrode (RHE) for hydrogen evolution reaction (HER) than that of NiP 2 and Ni 0.85 Se, which demonstrates the modulated electronic structure of Ni 0.85 Se|P. Our study will provide a new strategy for combining P-doped induced high crystallinity mixed anion transition metal complexes with MOF of hollow structures for energy storage device and HER.