Cobalt-Doped Ni10Mo/MoO2 Electrocatalysts as Stable and Efficient Bifunctional Catalysts for Sustained Overall Water Splitting and Alkaline Seawater Splitting.

Under the global carbon neutrality goals, hydrogen energy has garnered significant attention, with electrocatalytic technology serving as the core enabler for its efficient production. Developing low-cost bifunctional electrocatalysts is key to achieving overall water electrocatalytic decomposition. The reported cobalt-doped Ni10Mo/MoO2 (Co─Ni10Mo/MoO2) catalyst exhibits outstanding bifunctional activity for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media. The overpotentials for HER at 10 and 100 mA cm-2 are 42 and 168 mV, respectively, while OER overpotentials were 273 and 328 mV, respectively. This catalyst eliminates the traditional two-step process of hydrothermal + high-temperature calcination, dispensing with the hydrothermal pretreatment step. While maintaining catalytic performance, it simplifies the preparation process and optimizes costs, offering a more viable technical pathway for clean hydrogen production. Only 1.49 V and 1.55 V voltages are required to reach a current density of 10 mA cm-2 in overall alkaline water and alkaline seawater splitting, respectively. Furthermore, this Co─Ni10Mo/MoO2 catalyst demonstrates long-term stability for up to 1200 h during overall alkaline seawater splitting. Moreover, in practical applications, a solar panel can drive this highly efficient overall water-splitting process, demonstrating its capability to store solar energy in the form of O2 and H2.