Spark plasma sintered porous Ni as a novel substrate of NiSe@Ni self-supporting electrode for ultra-durable hydrogen evolution reaction.

Developing efficient and durable self-supporting catalytic electrodes is an important way for industrial applications of hydrogen evolution reaction. Currently, commercial nickel foam (NF)-based electrode has been widely used due to its good catalytic performance. However, the NF consisting of smooth skeleton surface and large pores not only exhibits poor conductivity but also provides insufficient space for catalyst decoration and sufficient adhesion, resulting in inadequate catalytic performance and poor durability of NF-based electrodes. In this paper, a novel three-dimensional porous Ni substrate with multangular skeleton surface and small pore structure was prepared by a modified spark plasma sintering technique, and subsequently NiSe@Porous Ni electrode with a large number of NiSe nanosheets uniformly distributed on the surface was obtained by one-step in-situ selenization. The electrode exhibits outstanding conductivity and catalytic hydrogen evolution reaction, providing a low overpotential of 183 mV at a current density of 100 mA cm. Due to the strong interfacial bonding between Ni and NiSe, the NiSe@Porous Ni electrode shows strong durability, which can work stably at 85 mA cm for more than 200 h. This work provides an effective strategy for the rational preparation of metal substrates for efficient and durable self-supporting catalytic electrodes.