Boosted Cr(VI) reduction performance over Cu 2 O/NH 2 -MIL-125 heterocomposite prepared via solution method

Metal–organic framework (MOF)-based heterocomposites have been widely applied as photocatalyst because they can supplement the shortcomings of single-phase MOF photocatalyst. In this article, we prepared Cu 2 O/NH 2 -MIL-125 heterocomposite via the reaction between NH 2 -MIL-125 and Cu(NO 3 ) 2 aqueous solution under room temperature. As indicated in the electron microscope investigation, the diameter of NM is about 182 nm, and the size of Cu2O nanoparticles is about 5 nm. The Cu 2 O/NH 2 -MIL-125 heterocomposite demonstrated higher performance compared with NH 2 -MIL-125, and the highest Cr (VI) degradation efficiency is determined as ~ 1.5 times as great as that of NH 2 -MIL-125. The improved photocatalytic activities of Cu 2 O/NH 2 -MIL-125 could be ascribed to the improved charge separation efficient and decreased carriers’ transfer resistance. Based on the radical species trapping experiment and electron paramagnetic resonance (EPR) measurement, a type-II heterojunction mechanism was proposed for the improved photocatalytic activity over the Cu 2 O/NH 2 -MIL-125 heterocomposite.