MOF-Derived Bimetallic Phosphides for High Performance Supercapacitors and Efficient Hydrogen Evolution Reaction

This study focuses on the synthesis of MOF-derived bimetallic phosphides with a novel morphology through a simple, economical and eco-friendly process. Characterization results indicate that the synthesized microspheres have a diameter of ∼1–3 µm decorated with nanoparticles on the surface with sizes of 20–70 nm, shaping the sprinkle-covered cake pop structures with a BET surface area of 140.36 m2 g−1. The obtained NiCo-P microspheres are employed as bifunctional electroactive materials in the preparation of electrochemical supercapacitor and HER catalyst. Notably, NiCo-P electrode demonstrates exceptional performance, with a high specific capacitance of 1010 F g−1 (404 C g−1) at 1 A g−1 with a capacity retention of 95.6% after 5000 charge–discharge cycles. The hybrid supercapacitor of NiCo-P//CB exhibits a high energy density of 56.08 Wh kg−1 at a power density of 36 kW kg−1 and specific capacitance of 161.75 F g−1 (255.57 C g−1) at 1 A g−1. Moreover, the as-synthesized NiCo-P shows excellent performance toward the HER, with a low overpotential of 72 mV to deliver a current density of 10 mA cm−2 and a Tafel slope of 43.52 mV dec-1. These excellent properties are attributed to the superiority of the phosphidation process, sufficient redox active centers and consequently enhanced electrical conductivity as well as the synergistic effects of Ni and Co with the phosphorous centers. The results demonstrate the potential of these materials for use in energy storage and conversion applications.