To get the optimization of reaction conditions, we used benzyl alcohol (1a) as a model substrate to explore photocatalytic selective oxidation of alcohols using oxygen molecules (Table ). Raw material benzyl alcohol does not transform in the absence of MOF catalyst or the presence of catalyst but dark conditions (Entry 12, 14). Additionally, only using NH 2 -MIL-125 (Ti) without NaBr is poor effective under 450 nm light at room temperature. (Table , Entry 3). The irradiation wavelength (450 nm) was chosen because the reaction unit irradiated with a single-wavelength visible light reaction module (Table , Entry 1, 4-6). When other solvents were used instead of the ethyl acetate, however, the conversion and yield dramatically decreased (Entry 7-9). KBr afforded the target component (Br -), but the reactivity was lower than that in the optimized conditions using the NaBr co-catalyst (Entry 1 vs Entry 10). It is worth noting that the benzyl alcohol was converted to benzaldehyde under a nitrogen atmosphere, and we speculated that aldehyde is the intermediate of the reaction (Entry 13). Also, thermo-catalytic had poor reactivity to light irradiation (Entry 15). These results indicate that the whole NH 2 -MIL-125 (Ti)/NaBr catalytic system is more suitable for the oxidation of alcohols than one of them.