Three-dimensional flower-like organic-dye-intercalated layered double hydroxide composite for efficient photocatalysis in heterogeneous flow chemistry

Abstract

A novel three-dimensional flower-like organic-dye-intercalated layered double hydroxide composite visible light photocatalyst RB@MgAl-LDH was prepared by soft template synthesis and anion exchange strategies. This composite catalyst demonstrates excellent catalytic activity in various organic transformations, including Knoevenagel condensation reaction and the cross-dehydrogenative coupling reaction. The leakage of intercalated organic dye is negligible, and the catalyst affords 87% yield of the reaction product even after 8 times of cycling. The good dispersion of the catalyst in the reaction system allows its application in the flow system without blockage, which is rare for heterogeneous catalytic systems. In the case of Knoevenagel condensation reaction, the reaction time could be reduced by 20 times (1 h to 3 min) to achieve very rapid organic synthesis under visible light irradiation, demonstrating good potential in industrial application of this novel catalyst.