JACS: Atomically Dispersed Ni Photocatalyst Enables Direct Production of Green Hydrogen from Seawater

Shoubhik Das and colleagues at the University of Bayreuth in Germany have developed an atomically dispersed nickel-based photocatalyst (Ni₀.₁₆@f₂-gC₃N₄) that enables efficient and stable photocatalytic hydrogen production directly from seawater or pure water without the need for sacrificial agents. The related research findings were published in the Journal of the American Chemical Society (J. Am. Chem. Soc.).

Under 390 nm light irradiation, the catalyst achieved a hydrogen production rate of 270 μmol/g/h in pure water, with a hydrogen yield of 119 μmol/g under natural sunlight. In seawater, the hydrogen production rate remained at 144 μmol/g/h, demonstrating excellent environmental adaptability. Characterization techniques such as HAADF-STEM and XAS confirmed that Ni exists in an atomically dispersed form. The catalyst maintained high activity after continuous operation for 720 hours (including 140 hours of illumination) and showed no significant decline in performance after 15 cycles of reuse. Mechanistic studies revealed that hydrogen production follows a two-step water splitting pathway: first, two-electron water oxidation generates H₂O₂ as an intermediate, followed by decomposition of H₂O₂ into O₂ and H₂, with Ni sites effectively promoting the decomposition of H₂O₂.