Degradation of carbamazepine in piezo-activation of persulfate systems: Comparison of PDS and PMS

Abstract

The choice of persulfate (PS) is crucial to the degradation and energy efficiencies for piezo-activation of PS (PE-PS) systems. Herein, a comparison between piezoelectrically activated peroxydisulfate (PDS) and peroxomonosulfate (PMS) using BaTiO3 are comparatively investigated for carbamazepine (CBZ) degradation. By contrast, the PE-PMS system achieves better degradation and mineralization of CBZ, as well as higher reaction stoichiometric efficiencies (%RSE). Nevertheless, the energy consumption of the PE-PDS system is only 9.69% of the PE-PMS system. The quenching test, chemical probe determination, and electron spin resonance (EPR) analysis suggest that the concentration of •OH, SO4∙-, and 1O2 except ∙O2- of the PE-PMS system, is higher than that of the PE-PDS system. The piezoelectric current density and carrier separation efficiency of the PE-PMS system are higher than that of the PE-PDS system, demonstrating that the piezoelectrically activated PMS has higher reactivity than piezoelectrically activated PDS. The ∙O2- and •OH are the primary ROS in the PE-PDS system, while 1O2 and •OH are the major ROS in the PE-PMS system. Additionally, CBZ is effectively degraded by both PE-PMS and PE-PDS systems from actual water sources. This work compares the performance, energy cost, and mechanism of PE-PMS and PE-PDS systems systematically. Hopefully, all of that is designed to tender a helpful reference for the choice of PS in piezocatalytic research and application.