Photocatalytic hydrogen generation from a visible-light responsive metal–organic framework system: the impact of nickel phosphide nanoparticles

Abstract

Herein, we report the performance of a photocatalytic system based on visible-light active MIL-125-NH₂ mixed with nickel phosphide (Ni₂P) nanoparticles. This combination boosts the H₂ evolution rate to an outstanding value of 894 μmol h⁻¹ g⁻¹ under visible-light irradiation, which is among the highest H₂ evolution rates reported to date for metal–organic frameworks (MOFs). The H₂ generation rate exhibited by Ni₂P/MIL-125-NH₂ is almost 3 times higher than that of the Pt/MIL-125-NH₂ system, highlighting the impact of the co-catalyst on photocatalytic water splitting. Additionally, our system outperforms the Ni₂P/TiO₂ system under UV-vis irradiation. The exceptional performance of Ni₂P/MIL-125-NH₂ is due to the efficient transfer of photogenerated electrons from MIL-125-NH₂ to Ni₂P, high intrinsic activity of Ni₂P and exceptional synergy between them. This system exhibits the highest apparent quantum yields of 27.0 and 6.6% at 400 and 450 nm, respectively, ever reported for MOFs.