3D flower-like porous P/S co-modulated NiNx-derived oxygen-containing reconstructed Ni-based heterostructure for efficient alkaline hydrogen evolution.

The development of economical, efficient, and durable non-precious metal electrocatalysts for the hydrogen evolution reaction (HER) is crucial for the scalable production of green hydrogen via water electrolysis. This work reports a NiNx-derived P/S-modulated oxygen-containing reconstructed Ni-based microflower heterostructure grown in situ on nickel foam (NF), denoted as NiNx/NF-P,S. This unique three-dimensional porous microflower architecture provides a large accessible surface area and abundant catalytic interfaces, while the strong integration with the NF substrate ensures excellent structural stability during prolonged HER operation. The incorporation of P and S promotes the construction of heterogeneous interfaces and regulates the local electronic structure, while surface reconstruction under alkaline HER conditions introduces oxygen-containing Ni species, resulting in reconstructed catalytic interfaces favorable for HER. Consequently, the obtained NiNx/NF-P,S catalyst exhibits outstanding HER activity in alkaline media, requiring low overpotentials of only 17 and 70 mV to achieve current densities of 10 and 100 mA cm-2, respectively. Furthermore, the catalyst maintains excellent long-term durability during continuous operation for 150 h. This work provides a promising strategy for constructing dynamically evolved non-precious metal heterostructured electrocatalysts.