Although MOF-composite materials usually exhibit improved mechanical properties, they often show decreased chemical and physical properties because the matrix may change the active sites and consequently, their catalytic activity can be reduced or even lost. Therefore, the assessment of their catalytic activity may help to test the chemical properties of those materials. More concretely, the photocatalytic activity of this family of materials was evaluated towards the oxidative coupling of amines to afford imines as a model reaction. Firstly, the activity of the composites containing 25, 50 and 75% of Ti-MOF loads was evaluated and compared to that of the pristine MIL-125-NH2. This study was performed using benzylamine (1a) and 1 mg of the corresponding material in dry acetonitrile, and the mixture was stirred under O2 atmosphere while irradiated at 450 nm for 48 h (Figure ). There is a linear relationship between the Ti-MOF content in the composite and its catalytic activity and consequently, the most catalytically active material contained 75% of MOF. This material [(Ti-MOF)0.75(IG)0.25] was able to achieve the corresponding imine in 87% of conversion, which is very close to that of the pristine material (95%). This result confirms the preservation of the catalytic activity of the MOF after the composite formation, which is surprising, because of composite fabrication includes a pelletisation and a thermal treatment that might damage the photoactive sites of this Ti-MOF. Moreover, the presence of a dense and non-photoactive phosphate-based glass would also be expected to worsen the catalytic properties. This deviation might be attributed to the small presence of the titanium-phosphate interactions at the interface that have been demonstrated as photoactive. It is important to mention that the reaction did not occur in the absence of light, oxygen, or material.