Boosting Photocatalytic Hydrogen Production by MOF-derived Metal Oxide Heterojunctions with a 10.0% Apparent Quantum Yield.

Photocatalytic hydrogen production offers an alternative pathway to establish a sustainable energy economy. While numerous photoactive materials exhibit potential for generating hydrogen from water, the synergy achieved by combining two different materials with complementary properties in the form of heterojunctions can significantly their photocatalytic activity. Our study describes the design and generation of the metal-organic framework-derived (MOF) metal oxide heterojunction composed of RuO2/N,S-TiO2. The RuO2/N,S-TiO2 is generated through the pyrolysis of MOFs, Ru- HKUST-1, and the amino-functionalized MIL-125-NH2. Among the various RuO2/N,S- TiO2 materials tested, the material characterized by the lowest RuO2 content, exhibited the highest hydrogen evolution rate, producing 10,761 μmol·hr-1·g-1 of hydrogen with an apparent quantum-yield of 10.0% in pure water. In addition to RuO2/N,S-TiO2, we generated two other MOF-derived metal-oxide heterojunctions, ZnO/N,S-TiO2 and In2O3/N,S-TiO2, leading to apparent quantum yields of 0.7% and 0.3%, respectively. The remarkable photocatalytic activity observed in RuO2/N,S-TiO2 is thought to be attributed to the synergistic effects arising from the combination of metallic properties inherent in the metal oxides, their band alignment, porosity, and surface properties inherited from the parent MOFs. The photocatalytic efficiency of RuO2/N,S-TiO2 was further demonstrated in actual water samples, producing hydrogen with a rate of 8,190 μmol·hr-1·g-1 in tap water.