Contribution of O in the efficient degradation of organic pollutants with Cu/CuO/CuO@N-C activated peroxymonosulfate: A Case study with tetracycline.

Peroxymonosulfate-mediated advanced oxidation processes (PMS-AOPs) degrading organic pollutants (Tetracycline (TC) as an example) in water with singlet oxygen (O) as the main reactive oxygen has received more and more attention. However, the generation mechanism of O is still unclear. Consequently, this study investigates the O formation mechanism during the activated PMS process using a nitrogen-copper-loaded carbon-based material (Cu/CuO/CuO@N-C), synthesized by thermally decomposing organobase-modified HKUST-1 via a one-pot method. It was discovered that incorporating an organobase (Benzylamine) into the metal organic framework (MOF) precursor directs the MOF's self-assembly process and supplements its nitrogen content. This modification modulates the Nx-Cu-Oy active site formation in the material, selectively producing O. Additionally, O was identified as the dominant reactive oxygen species in the Cu/CuO/CuO@N-C-PMS system, contributing to TC degradation with a rate of 70.82%. The TC degradation efficiency remained high in the pH range of 3-11 and sustained its efficacy after five consecutive uses. Finally, based on the intermediates of TC degradation, three possible degradation pathways were postulated, and a reduction in the ecotoxicity of the degradation products was predicted. This work presents a novel and general strategy for constructing nitrogen-copper-loaded carbon-based materials for use in PMS-AOPs.