LAUSR

Abstract Introduction of linker defects in a visible light responsive metal–organic framework (MOF) photocatalyst, MIL-125(Ti)–NH2, has been attempted to improve its reactivity. MIL-125(Ti)–NH2, composed of Ti-oxo cluster and 2-aminoterephthalic acid organic linker, was synthesized by a solvothermal method and then underwent photothermal treatments. XRD measurements and 1H NMR spectroscopy revealed that linker elimination from the MOF occurred by a simultaneous visible-light irradiation and mild heating at 313 K in water containing electron donor, while keeping its framework structure. The resultant defective MOF effectively promotes visible light-driven H2 evolution reaction from water containing electron donor without using any cocatalysts, and its activity is comparable to that of Pt cocatalysts-loaded crystalline MIL-125(Ti)–NH2. When pristine MIL-125(Ti)–NH2 without cocatalysts is used in the reaction, the reduction of Ti species in Ti-oxo clusters from Ti4+ to Ti3+ takes place instead of reducing protons to evolve H2; thereby, linker defect introduction caused by the photothermal treatment was concluded to play a role in creating effective reaction sites for proton reduction on Ti-oxo clusters.