The design and synthesis of efficient, inexpensive, and long-term stable heterostructured electrocatalysts with high-density dislocations for hydrogen evolution reaction in alkaline media and seawater are still a great challenge. An amorphous/crystalline/amorphous sandwiched structure with abundant dislocations were synthesized through thermal phosphidation strategies. The dislocations play an important role in the hydrogen evolution reactions. Copious dislocation defects, combined with cracks, and the synergistic interfacial effect between crystalline phase and amorphous phase regulate the electronic structure of electrocatalyst, provide more active sites, and thus endow the electrocatalysts with excellent catalytic activity under alkaline water and seawater. The overpotentials of P–NiMoO4 at 10 mA/cm2 in 1 M KOH aqueous solution and seawater are 45 and 75 mV, respectively. Additionally, the P–NiMoO4 electrocatalyst exhibits long-term stability over 100 h. This study provides a simple approach for synthesizing amorphous/crystalline/amorphous sandwiched non-noble-metal electrocatalysts with abundant dislocations for hydrogen evolution reaction.
Jian Tang,Jun Fang,Haochen Yao,Jianglong Wei,Geng Gao,Yusong Yang,Bin Yang,Yaochun Yao
Hierarchical structure design and heterostructure engineering are effective strategies for enhancing hydrogen evolution reaction (HER) performance, yet their synergistic integration remains underexplored. In this work, a novel hierarchical P-NiMoO 4 @Net-like Ni 2 P heterostructure HER electrocatalyst was prepared via a two-step hydrothermal method followed by low-temperature phosphorization. The three-dimensional net like Ni 2 P was closely integrated with one-dimensional phosphorus-doped NiMoO 4 micro/nanorod arrays, enabling hierarchical structural assembly and the formation of synergistic heterointerfaces. The hierarchical structure significantly increased active site exposure, with a double-layer capacitance of 254.4 mF cm −2 , more than five times that of single-component Ni 2 P (48.4 mF cm −2 ). Density functional theory calculations revealed that the heterostructure lowered the d-band center of active Ni 3 sites and optimized the hydrogen adsorption energy, thereby enhancing HER activity. The P-NiMoO 4 @Net-like Ni 2 P catalyst exhibited an alkaline HER overpotential of 49 mV at a current density of 10 mA cm −2 . It also maintained stable operation for 100 h at 10mA cm −2 and 120 h at 100mA cm −2 . This study demonstrates the potential of integrating hierarchical and heterostructural strategies, providing a reference for advanced nanostructured catalyst development.