Hierarchical NiMoP₂-Ni₂P with amorphous interface as superior bifunctional electrocatalysts for overall water splitting

Producing highly efficient bifunctional catalyst for the generation of hydrogen and oxygen through overall water splitting is an emerging direction in electrocatalysis. Herein, a dandelion-like hierarchical NiMoP₂-Ni₂P (nanowire/nanoparticle) heterostructure was synthesized for efficient electrochemical water splitting. The NiMoP₂-Ni₂P heterostructures grown on carbon cloth as a freestanding integrated electrode exhibited excellent oxygen evolution reaction (OER) activity and hydrogen evolution reaction (HER) activities with low overpotentials (258 mV and 53 mV to reach 10 mA cm⁻² for the OER and HER, respectively), and small Tafel slope (45 mV dec^-1 and 58 mV dec^-1 for the OER and HER, respectively). Moreover, the NiMoP₂-Ni₂P heterostructure can act as both anode and cathode catalysts for overall water splitting with low overall potential of 1.48 V at 10 mA cm⁻². Density functional theory (DFT) combined with structural probes suggests that the amorphous heterogeneous interfaces play an essential role in enhanced catalytic performance.