Water-regulated 2D Ni-MOF-derived heat-sheared Nano-Ni@TC for efficient hydrogen evolution

Hydrogen energy has garnered significant attention due to its high calorific value and minimal environmental impact. However, the high-current electrolysis of water encounters challenges such as insufficient active sites and the disruptive effects from rapidly generated bubbles. In this paper, a small amount of water was introduced to modify the strong coordination ability of metal ions with organic ligands, and prepared 2D Ni MOFs. Subsequently, thin carbon-armed Ni-based catalysts (Ni@TC NPs) were prepared through nickel-assisted low-temperature pyrolysis. Unlike other 3D MOFs, the 2D MOF thin sheets prepared in this work can decompose at low temperatures due to its thin thickness, and the exposed Ni will accelerate the carbonization of surrounding organic groups, resulting in the formation of smaller and uniformly distributed thin carbon-armored Ni@TC NPs at lower temperature. Serving as a Hydrogen Evolution Reaction (HER) electrocatalyst, Ni@TC NPs demonstrate exceptional electrocatalytic performance (low overpotential of 36.6 mV at 10 mA cm−2, and low Tafel slope of 91.06 mV dec−1), and long-term stability (over 50 h at 440 mA cm−2). The electronic modulation between the thin carbon armor and the metal center endows Ni@TC NPs with excellent kinetic performance, while the carbon armor provides protection in alkaline environments. In addition, the small and dense bubbles that quickly escape greatly reduce the bubble shielding and oscillation effects on the electrode surface, enabling Ni@TC NPs to work stably under high currents.