BackgroundNiCo-based phosphides are given more concerns as superior hydrogen evolution reaction (HER) catalysts in electrolysis industrialization. Nevertheless, the single NiCo-based phosphides have finite active sites and electronic structures to limit their HER behaviors. MethodsNiCoP nanosheets anchored on Ni foam (NF) are first synthesized by hydrothermal reaction and phosphorization technique. Then, the NiCoP nanosheets are coated by the small size of NiCoP nanoparticles using the same methods to obtain NiCoP nanoparticles@NiCoP nanosheets (NiCoP NPs@NiCoP NSs/NF), which possess abundant active sites and strong electron structures. Significant findingsAs expected, the NiCoP NPs@NiCoP NSs/NF display superior HER activity (a small overpotential of 87 mV@50 mA·cm−2 and Tafel slope of 155 mV·dec−1) and durability in 1 M KOH solution at 313 K. In addition, an electrolytic cell is also assembled by applying NiCoP NPs@NiCoP NSs/NF as a cathode, and NiCo2Al-LDHs@ZnFeAl-LDHs/NF as an anode, which also exhibits admirable electrocatalytic behaviors. Hence, these results imply that NiCoP NPs decorated on the surface of NiCoP NSs play a significant role in regulating the electronic structure and boosting electrocatalytic active sites of NiCoP NPs@NiCoP NSs, which provides a possibility to achieve great application potential in the electrolytic water industry.