MOF-derived CuCo carbon microspheres assembled with nitrogen-doped carbon nanotubes as PMS activator for the efficient degradation of p-nitrophenol

Abstract

Due to the complex structure of metal–carbon-based catalysts derived from metal-organic frameworks (MOFs), it is difficult to clarify the active sites and catalytic mechanisms. Constructing of structure–activity relationship is conducive for identifying active center, but there is still a gap in the bimetal-carbon-based catalysts/PMS systems. Here, we report a highly efficient and stable CuCo bimetal-nitrogen doped carbon catalyst (CuCo@C-N) for the activation of PMS for efficient degradation of PNP. By manipulating the catalyst structure, establishing the structure–activity relationship and combining with DFT calculation, the non-metallic active centers were determined, including defects, C=O and graphite N. Co was the only metal active center, and the presence of Cu accelerated the redox cycle of the system. The degradation of PNP was dependent on electron transfer and ROS activation. The metal active center was used to generate sulfate radicals (SO₄^•−), and the non-metal active sites accelerated electron transfer and non-radical pathways to generate ¹O₂.