g-C3N4/Uio-66-NH2 nanocomposites with enhanced visible light photocatalytic activity for hydrogen evolution and oxidation of amines to imines

Abstract

g-C₃N₄/Uio-66-NH₂ (CNUIO) nanocomposites were prepared by growing an NH₂-mediated zirconium-based metal–organic framework (Uio-66-NH₂) in the presence of g-C₃N₄ nanotubes. CNUIO exhibited efficient photocatalytic performance in the oxidation of amines to imines and hydrogen production under visible light illumination. The optimal Uio-66-NH₂ content in CNUIO was 16.7 wt% with a H₂-generation rate of 152.2 μmol h⁻¹, which is about 1.7 and 39 times as high as those of g-C₃N₄ and Uio-66-NH₂, respectively. The optimal conversion rate of benzylamine was 58.9%, which is about 3.4 and 10.5 times as high as those of g-C₃N₄ and Uio-66-NH₂, respectively. The probable photocatalytic mechanism of the CNUIO composite was investigated. This work provides a new insight into the fact that g-C₃N₄/MOF photocatalysts have great potential application in hydrogen production and organic synthesis.