Enhancing Photocatalytic Hydrogen Production via the Construction of Robust Multivariate Ti-MOF/COF Composites

Titanium metal-organic frameworks (Ti-MOFs), as an appealing type of artificial photocatalyst, have shown great potential in the field of solar energy conversion due to their well-studied photoredox activity (similar to TiO₂ ) and good optical responsiveness of linkers, which serve as the antenna to absorb visible-light. Although much effort has been dedicated to developing Ti-MOFs with high photocatalytic activity, their solar energy conversion performances are still poor. Herein, we have implemented a covalent-integration strategy to construct a series of multivariate Ti-MOF/COF hybrid materials PdTCPP⊂PCN-415(NH₂ )/TpPa (composites 1, 2, and 3), featuring excellent visible-light utilization, a suitable band gap, and high surface area for photocatalytic H₂ production. Notably, the resulting composites demonstrated remarkably enhanced visible-light-driven photocatalytic H₂ evolution performance, especially for the composite 2 with a maximum H₂ evolution rate of 13.98 mmol g^-1  h^-1 (turnover frequency (TOF)=227 h^-1 ), which is much higher than that of PdTCPP⊂PCN-415(NH₂ ) (0.21 mmol g^-1  h^-1 ) and TpPa (6.51 mmol g^-1  h^-1 ). Our work thereby suggests a new approach to highly efficient photocatalysts for H₂ evolution and beyond.