Efficient peroxymonosulfate activation in electron-rich/poor reaction sites induced by copper-iron oxide heterojunctions/interfaces: Performance and mechanism

The development of the efficient material for peroxymonosulfate (PMS) activation is of great importance for water treatment. Herein, a novel magnetic Cu/gamma-Fe2O3 catalyst with a dual reaction center (DRC) and abundant heterojunctions/interfaces was constructed, in which uniform composite Cu/gamma-Fe2O3 nanoparticles were anchored on a thin continuous carbon framework. The asymmetric configuration of the Cu/gamma-Fe2O3 catalyst significantly promotes the adsorption and activation of PMS by strengthening Fe-OH coordination and reducing the adsorption energy barrier of interfacial Cu sites. The efficient conversion of SO4 center dot- and the generation of singlet oxygen (O-1(2)) were realized in the Cu and gamma-Fe2O3 domains, respectively, owing to the electron polarization distribution in Cu/gamma-Fe2O3. Through synergetic multi-pathway activation, tetracycline (TC) underwent efficient degradation over a wide pH range (3-11), and the degradation efficiency was not inhibited by common ions. The reaction rate of Cu/gamma-Fe2O3 (0.685 min(-1)) was 5.1 and 9.8 times higher than that of the non-DRC Cu and gamma-Fe2O3 catalysts, respectively. Furthermore, the Cu/gamma-Fe2O3 + PMS system exhibited excellent stability and significantly low metal leaching. This work provides a possible approach to address the application bottlenecks of metal-based catalysts as well as to develop novel environmental remediation materials.

Automated summary

A new magnetic Cu/gamma-Fe2O3 catalyst was developed with dual reaction centers and abundant heterojunctions/interfaces for efficient activation of PMS in water treatment. The catalyst showed enhanced adsorption and activation of PMS, leading to efficient degradation of tetracycline over a wide pH range, with a reaction rate significantly higher than that of traditional catalysts.