Fabrication of Octahedral Cu@Graphitic Carbon Cage Complex Porous Structures and Their Microwave-Driven Catalytic Activity

摘要

A novel porous octahedral Cu@graphitic carbon cage (Cu@GCC) was successfully fabricated by rapid room-temperature synthesis of a Cu-based metal organic framework (MOF) with further pyrolysis in N-2. The as-obtained Cu@GCCs show a unique structure where well-dispersed Cu nanoparticles (NPs) were encapsulated in porous carbon cages. Compared to Cu/Cu2O@GCCs, CuO/Cu2OP GCCs, a graphitic carbon matrix, and pure Cu, the Cu@GCCs exhibited the best catalytic activity toward the degradation of lomefloxacin (LOM) and methylene blue (MB) under microwave irradiation (MI). Microwave -driven enhanced catalytic activity of Cu@GCCs was mainly ascribed to synergistic contributions of plasmonic Cu NPs and carbon cages as well as their unique open porous structure facilitating the mass transfer and highly efficient microwave energy harvesting. The Cu NPs play a pivotal role of oxidation active center in this catalytic process. The longevity and reusability of Cu@GCCs were enhanced by the protective role of the carbon layer. The main active species were identified to be holes (h(+).) and superoxide radicals (center dot O-2(-)) by various scavengers, and new insights into the catalytic mechanism from the localized surface plasmon resonance (LSPR) effect of metallic nanostructures were also provided. This work offers a new strategy for the design of metal@GCC catalysts and explores their potential applications in environmental remediation.