Multifunctional 0D–2D Ni2P Nanocrystals–Black Phosphorus Heterostructure

0D transition metal phosphides (TMPs) nanocrystals (NCs)–2D ultrathin black phosphorus (BP) heterostructure (Ni 2 P@BP) have been synthesized via a facile sonication‐assisted exfoliation followed by a solvothermal process. Compared with the bare BP, the specially designed Ni 2 P@BP architecture can enhance the electrical conductivity (from 2.12 × 10 2 to 6.25 × 10 4 S m –1 ), tune the charge carrier concentration (from 1.25 × 10 17 to 1.37 × 10 20 cm –3 ), and reduce the thermal conductivity (from 44.5 to 7.69 W m –1 K –1 ) at 300 K, which can be considered for multiple applications. As a result, the Ni 2 P@BP exhibits excellent Li storage properties and high hydrogen evolution reaction electrocatalytic activities. The Ni 2 P@BP shows improved Li diffusion kinetics (e.g., the Li ions diffusion coefficient increases from 1.14 × 10 –14 cm 2 s –1 for pure BP nanosheets to 8.02 × 10 –13 cm 2 s –1 for Ni 2 P@BP). In addition, the Ni 2 P@BP electrode sustains hydrogen production with almost unchanged activity over 3000 cycles, which indicates its good chemical stability when operating under strong reducing environment.