Immobilization of Au nanoparticles on black phosphorus modified spherical covalent organic frameworks for the flow-through reduction of 4-nitrophenol

Covalent organic frameworks (COFs), due to their unique structure and morphology, manifest great potential as active substrates to support noble metals for sustainable catalytic applications. However, it is still a challenge for efficient and effective catalysis using these kinds of COFs-based catalysts. Here, black phosphorus (BP) nanosheets modified spherical COFs (SCOFs) were synthesized, followed by the immobilization of Au nanoparticles (Au NPs) to fabricate Au NPs/BP/SCOFs microspheres. The as-prepared Au NPs/BP/SCOFs microspheres were then filled in a column for the continuous catalytic reduction of 4-nitrophenol. A fast and highly efficient flow-through catalysis of 4-nitrophenol with a reduction efficiency of 99% under the flux of 2500 L m−2 h−1 was obtained. Furthermore, a stable catalytic performance under flow-through process was exhibited with only 0.13 wt. % of total Au NPs releasing after testing for 24 h. The strategy for designing COFs-based substrates with enhanced electron transfer and controllable morphology would develop a new route to promote the application of these kinds of COFs-based catalysts.