Light‐Promoted Hydrazine Dehydrogenation over Ni/NH ₂ ‐MIL‐125: Unraveling Mechanisms for Efficient Hydrogen Production

Developing efficient, low-cost, and durable catalysts for the complete dehydrogenation of hydrous hydrazine (N₂H₄·H₂O) remains a significant challenge. Herein, a high-performance, visible-light-responsive Ni-loaded amino-functionalized MIL-125 (Ni/NH₂-MIL-125) catalyst is fabricated via a facile chemical reduction method, which, for the first time, enables visible-light-enhanced N₂H₄ dehydrogenation using a non-precious metal catalyst. Under visible light irradiation, Ni/NH₂-MIL-125 achieves a turnover frequency (TOF) of 220.2 h^-1 at 323 K, more than twice that in the dark (108.1 h^-1) and outperforms most reported non-precious metal catalysts. Characterizations and theoretical calculations reveal that the enhanced light-promoted activity arises from light-induced electron transfer from the NH₂-MIL-125 to the Ni active sites, which synergistically strengthens N₂H₄ adsorption and lowers the energy barrier for N─H bond cleavage, the rate-determining step. This work establishes visible-light promotion as a powerful strategy to enhance non-precious metal catalysis and offers a promising avenue for nitrogen-based hydrogen storage systems.