The enhanced photocatalytic activity of TiO2(B)/MIL-100(Fe) composite via Fe–O clusters†

Black TiO₂ and metal–organic frameworks (MOF) are great materials with light-harvesting ability, redox power and consequently catalytic activity. Here, the integration of MIL-100(Fe) with TiO₂(B) composite was designed for photocatalytic application, which greatly promoted light-harvesting and charge transfer. As expected, the integrated TiO₂(B)/MIL-100(Fe) composite showed high photocatalytic activity due to unique Fe–O–Ti bonds that were constructed, which acted as an electronic tunnel to reduce electronic transfer resistance between MIL-100(Fe) and TiO₂(B). In addition, the presence of Fe–O clusters in MIL-100(Fe) can also promote the charge dissociation and improve catalytic activity via the Fe³⁺/Fe²⁺ redox cycle. This achievement would help us to understand and design charge transfer pathways in the integration of MOF/semiconductor photocatalysts.