MOF-derived Cu0/C activation of molecular oxygen for efficient degradation of sulfamethazine

Zero-valent copper (ZVC) has shown potential as an oxygen activator for the degradation of organic pollutants from aqueous solution. Nevertheless, the high leaching of copper ions and the demand for acidic condition limited its application. In this study, a novel mesoporous carbon hybrid loaded zero-valent copper (Cu0/C) was successfully synthesized from Cu-based metal-organic framework (Cu3(BTC)2) through a pyrolysis method and applied to efficiently degrade sulfamethazine (SMT) at neutral pH under aeration condition. The performance of Cu0/C composite for the activation of molecular oxygen was evaluated based on the effect of different reaction parameters, such as, initial SMT concentration, initial pH, activator dosage and reaction temperature. The results showed a high efficiency for SMT removal over a broad pH range (3.0-7.0). Moreover, the Cu0/C composite exhibited excellent stability and reusability for SMT degradation, and a 96.7% SMT removal and a 68.8% total organic carbon (TOC) conversion were achieved at pH 5.8 after continuous three cycles. Combined with the determination results of reactive oxidizing species and physical-chemical characterization, cupryl species (Cu3+) rather than center dot OH produced by the reaction of the in-situ generated H2O2 with Cu+ were the major reactive species. Additionally, the possible reaction mechanism of Cu0/C activated oxygen was tentatively proposed.

Automated summary

In this study, a novel mesoporous carbon hybrid loaded zero-valent copper (Cu0/C) was successfully synthesized and applied for efficient degradation of sulfamethazine (SMT) at neutral pH. The Cu0/C composite showed high efficiency for SMT removal over a broad pH range and exhibited excellent stability and reusability. The major reactive species were identified as cupryl species (Cu3+) rather than center dot OH produced by the reaction of in-situ generated H2O2 with Cu+.