A novel porous nickel-based electrode for durable and efficient hydrogen evolution over 720 h

The challenge of simultaneously enhancing the catalytic activity and service life of Ni-based self-supported electrodes is one of the major bottlenecks in the development of alkaline water electrolysis for hydrogen production. To address this issue, we propose a novel Mo-doped Ni 3 S 2 @porous Ni self-supported electrode (denoted as MNS@PN) and demonstrate its outstanding performance in the hydrogen evolution reaction (HER). First, a porous Ni substrate with a rough surface was fabricated via powder metallurgy, followed by in-situ loading of the catalytic phase on the substrate using a one-step hydrothermal sulfurization method. In a 1.0 M KOH solution, the MNS@PN electrode exhibits a significantly lower overpotential of 213 mV at a current density of 100 mA cm −2 compared to traditional Ni-based electrodes. Notably, at higher current densities (>215 mA cm −2 ), the overpotential of the MNS@PN electrode is even lower than that of a Pt plate electrode, demonstrating its potential under high current conditions. The MNS@PN electrode also shows excellent stability, with almost no performance degradation after 10,000 cyclic voltammetry (CV) tests, and it operates stably for over 720 h at a current density of 150 mA cm −2 . DFT calculations combined with experimental data indicate that Mo doping significantly improves the electronic structure of Ni 3 S 2 , enhancing its hydrogen adsorption capability and thus boosting the catalytic activity. In conclusion, the MNS@PN electrode exhibits low overpotential and excellent durability, showing promise for industrial water electrolysis applications. • A self-supported Mo-doped Ni 3 S 2 @porous Ni electrode (MNS@PN) was fabricated. • The electrode exhibits excellent catalytic activity and stability for over 720 h. • Mo doping significantly optimizes the electronic structure and improves the HER activity.