One-pot synthesis of mesoporous silicas supported Cu single-atom and CuO nanoparticles for peroxymonosulfate-activated degradation of tetracycline over a wide pH range

Abstract

Peroxymonosulfate activated heterogeneous Fenton-like catalytic reactions are promising in degradation of recalcitrant pollutants. Mesoporous silicas supported high-dispersion Cu species, as a kind of conventional heterogeneous catalysts for extensive applications, are rarely studied for their degradation efficiency in peroxymonosulfate-triggered reactions. In this work, one-pot incorporation method was employed to generate simultaneously Cu single-atom, Cu nanoparticles in mesoporous silicas (like the sample of Cu/Si-3 with 0.68 wt% of Cu) using sodium copper chlorophyllin as Cu source by calcining directly in air atmosphere. Several characterizations confirm the coexistence of Cu single-atom, Cu nanoparticles and mesopore with uniform size distribution. Activated by peroxymonosulfate, Cu/Si-3 was found to be efficient in degradation of tetracycline throughout a wide pH range of 2–11. The radicals of S O 4 g − , ⋅ O H and O 1 2 played their role in the degradation reaction. The underlying catalytic mechanism of the Fenton-like reaction was speculated on the basis of analysis of reactive oxygen species. This work has important implication in reasonable design and fabrication of catalysts with high-dispersion metal and controllable synthesis of functional mesoporous materials, as well as in proper disposal of recalcitrant pollutants including tetracycline. • Composite of Cu single-atom and CuO nanoparticles simultaneously generated by one-pot synthesis under air atmosphere. • Successful preparation of mesoporous materials with uniform size distribution. • Cu single-atom catalysts obtained by calcination without protection of inert gas. • The obtained highly dispersed Cu species favourable in degradation of tetracycline. • The catalyst's wide working pH window of 2–11.