Strong electronic couple engineering of transition metal phosphides-oxides heterostructures as multifunctional electrocatalyst for hydrogen production

Rational design of heterogeneous electrocatalysts is an effective approach to synergistically promote hydrogen production for renewable energy conversion. Herein, a selective phosphorization strategy by controlling the only phosphorization of higher activity Ni atoms in precursor to construct Ni2P/MoO2/NF heterostructure nanorods arrays (Ni2P/MoO2/NF HNRs) electrocatalyst is realized. By effective interface construction, the strong electronic coupling effect is induced by spontaneously electron transfer across Ni2P/MoO2 heterointerface, which modulates the electronic structure and enhances intrinsic catalytic activity, leading to outstanding electrocatalytic activities and long-time durability in alkaline electrolyte. The Ni2P/MoO2/NF HNRs present ultralow overpotential of 34 mV at 10 mA·cm−2 for hydrogen evolution reaction. Impressively, when coupled it for urea-assisted electrolyzer, the potential as low as 1.35 V is needed to achieve 10 mA·cm-2. Experimental and density functional theory results reveal that the strong electronic coupling effect enhances the synergy effect between Ni2P and MoO2, beneficial for boosting the H2 production.