Encapsulating Copper Nanocrystals into Metal–Organic Frameworks for Cascade Reactions by Photothermal Catalysis

Composite materials with multifunctional properties usually possess synergetic effects in catalysis toward cascade reactions. In this work, a facile strategy to the encapsulation of octahedral Cu2O nanocrystals (NCs) by metal–organic frameworks (MOFs) is reported, and an oriented growth of MOF enclosures (namely, HKUST‐1) around Cu2O NCs with desired feedstock ratio is achieved. The strategy defines the parameter range that precisely controls the etching rate of metal oxide and the MOF crystallization rate. Finally, the Cu@HKUST‐1 composites with uniform morphology and controlled MOF thickness have been successfully fabricated after the reduction of Cu2O to Cu NCs in HKUST‐1. The integration of Cu NCs properties with MOF advantages helps to create a multifunctional catalyst, which exhibits cooperative catalytic activity and improved recyclability toward the one‐pot cascade reactions under mild conditions involving visible‐light irradiation. The superior performance can be attributed to the plasmonic photothermal effect of Cu NCs, while HKUST‐1 shell provides Lewis acid sites, substrates and H2 enrichment, and stabilizes the Cu cores. In this work, the oriented growth of HKUST‐1 on Cu2O nanocrystals (NCs) in a one‐to‐one structure has been successfully fabricated by precisely controlling the rates between metal oxide etching and HKUST‐1 formation. Upon reduction of Cu2O to Cu NCs, the obtained Cu@HKUST‐1 exhibits synergistically enhanced catalytic performance toward the cascade reactions under mild conditions involving visible‐light irradiation.