Covalent synthesis of Ti-MOF for enhanced photocatalytic CO₂ reduction

Ti based Metal-organic frameworks materials, with their high surface area, visible light responsiveness, and abundant catalytic active sites, have emerged as efficient photocatalysts. However, the number of reports on titanium-based MOFs is limited, mainly due to the challenges associated with their synthesis. In this study, based on the covalent strategy of imine condensation, a novel Ti-MOF was designed and synthesized by rational selection of aldehyde ligands. The photocatalytic CO₂ reduction performance of the Ti-MOF was evaluated, and it exhibited a remarkable generation rate of formate ions at 46.0 μmol g⁻¹ h⁻¹, which is more than 6 times higher than that of MOF-902 constructed with the same titanium cluster. The rational selection of aldehyde ligands resulted in a relatively superior band structure for the Ti-MOF, characterized by a narrowed bandgap and a significantly negative shift of the conduction band, leading to enhanced photocatalytic ability.