Ni(dmgH)2 complex coupled with metal-organic frameworks MIL-101(Cr) for photocatalytic H2 evolution under visible light irradiation

Abstract

Metal-organic frameworks (MOFs) have been tremendously used as photocatalysts for H2 generation in recent years. Lacking native active sites (so-called co-catalyst) for H2 generation motivates the incorporation of noble metals and their molecular complexes, hydrogenase active site mimics into MOFs to promote H2 generation. We herein report an noble-metal-free photocatalytic H2 generation system consisting of Erythrosin B dye-sensitized MIL-101(Cr) as a light absorber and Ni(dmgH)2 as a co-catalyst. It is found that Ni(dmgH)2 can serve as an efficient co-catalyst to boost H2 generation in the presence of triethanolamine (TEOA) as an electron donor under visible light irradiation. The optimal MIL-101(Cr)/Ni(dmgH)2 hybrid (5 wt% Ni(dmgH)2) displays a hydrogen H2 rate of 45.5 μmol h−1, which is 10 times greater than the control sample without Ni(dmgH)2 loading. This paper provides a novel design route for active H2 generation systems by combining molecular complexes of earth-abundant metal and MOFs photocatalysts.