Yuanzhi Luo,Sisi Wu,Pan Wang,Hariprasad Ranganathan,Zhicong Shi
The rational design of high-performance non-noble metal electrocatalysts at large current densities is important for the development of sustainable energy conversion devices such as alkaline water electrolyzers. However, improving the intrinsic activity of those non-noble metal electrocatalysts remains a great challenge. Therefore, Ni 2 P/MoO x decorated three-dimensional (3D) NiFeP nanosheets (NiFeP@Ni 2 P/MoO x ) with abundant interfaces were synthesized using facile hydrothermal and phosphorization methods. NiFeP@Ni 2 P/MoO x exhibits excellent electrocatalytic activity for hydrogen evolution reaction (HER) at a high current density of −1000 mA cm −2 with a low overpotential of 390 mV. Surprisingly, it can operate steadily at a large current density of −500 mA cm −2 for 300 h, indicating its long-term durability under high current densities. The boosted electrocatalytic activity and stability can be ascribed to the as-fabricated heterostructures via interface engineering, leading to modifying the electronic structure, improving the active area, and enhancing the stability. Besides, the 3D nanostructure is also beneficial for exposing abundant accessible active sites. Therefore, this research proposes a considerable route for fabricating non-noble metal electrocatalysts by interface engineering and 3D nanostructure applied in large-scale hydrogen production facilities.
The instinct scaling relations between the adsorption energies of key intermediates during OER lead to large overpotential for water/seawater splitting. Herein, we develop a new strategy to fabricate amorphous nickel-iron phosphides (NiFeP) with controllable morphologies as high-performance catalysts for overall seawater splitting. The ligand effect of P tunes the electronic states of the oxidized NiFe sites, thus breaks the scaling relations for OER and reduce the adsorption energy gap between HO* and HOO* from 3.08 eV to 2.62 eV. The NiFeP nanostructures exhibit extraordinarily low overpotentials of 129 mV for OER and 126 mV for HER at 100 mA cm −2 in simulated alkaline seawater, which outperform the best reported electrocatalysts. They could also be operated at 1.57 V with 100 mA cm −2 in a two-electrode electrolyzer and work for more than 500 h. Our work may provide a universal guidance for the design of highly active seawater splitting electrocatalysts.
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