Tunable Ni2P@polypyrrole Nanocomposites for Efficient Hydrogen Evolution and High-Performance Supercapacitors.

A composition-dependent Ni2P@PPy nanocomposite is developed as a multifunctional electrocatalyst-supercapacitor. Upon controlling Ni2P loading, Ni2P@PPy switches functionality, delivering efficient hydrogen evolution (102 mV at 10 mA cm-2) or ultrahigh supercapacitor performance (2961 F g-1 at 10 A g-1), highlighting a rational strategy for integrated energy conversion and storage.