Fabrication of NH2-MIL-125 Nanocrystals for High Performance Photocatalytic Oxidation
To develop facile route for improving the photocatalytic performances of metal-organic frameworks is of great importance. Herein, we demonstrate for the first time that downsizing the NH2-MIL-125 crystals to nanometer scale can greatly improve its activity for photocatalytic benzylamine oxidation reaction. Under mild conditions, the conversion of benzylamine into N-benzylbenzaldimine reaches 98.5% at 9 h with the turnover frequency (TOF) value of 1063 μmol g-1 h-1 as catalyzed by NH2-MIL-125 nanocrystals, much superior to NH2-MIL-125 microcrystals (conversion 55.9% and TOF 570 μmol g-1 h-1, respectively). The as-synthesized NH2-MIL-125 nanocrystals have small crystal size, abundant oxygen vacancy, enhanced light absorption ability, strong oxygen reduction capacity, strengthened separation capability and transfer efficiency of photoexcited charges, conferring them high photocatalytic performance for benzylamine oxidation reaction.