In Situ Synthesis of Honeycomb Nanorods Ni3S2@NiCo-Layered-double Hydroxide/Nickel Foam Electrocatalysts with High Performance Electrocatalytic Hydrogen Production

The design and development of composite nanomaterial structures holds a significant importance in the synthesis of highly efficient electrocatalysts. Nevertheless, it is still challenging to obtain advanced electrocatalysts with excellent catalytic activity and stability over the long term. In this study, we successfully obtained a unique nanostructures Ni3S2@NiCo- layered-double hydroxide (LDH)/ nickel foam (NF) by vertically and uniformly growing Ni3S2 ultrafine nanosheets onto the NiCo-LDH surface using NiCo LDH as the backbone. The resulting catalyst possesses a distinctive three-dimensional needle-like nanorod structure and its surface is comprised of numerous two-dimensional cross defects enriched with honeycomb-like ultrathin nanosheets. This nanostructure design promotes an efficient electron transfer, offers abundant active sites, and facilitates the release of gases during the catalytic reactions. Furthermore, the electrocatalyst's stability and reactivity are greatly enhanced by the synergistic interaction of NiCo-LDH with Ni3S2. Comparative analyses revealed that the Ni3S2@NiCo LDH/NF catalysts, with their unique three-dimensional needle-like nanorod structure, exhibit superior catalytic performance for the hydrogen evolution reaction (HER) with an electric density of 10 mAcm-2 and a low over-potential of 151 mV. Remarkably, the catalytic performance of Ni3S2@NiCo LDH/NF electrocatalysts surpasses that of most non-precious metal catalysts and even some noble metal catalysts as reported. In conclusion, the strategy proposed in this study for the construction of cost-effective, extremely active, and stable electrocatalysts holds a great potential for future advancements in the hydrogen energy conversion applications.