Enhanced and Synergistic Peroxymonosulfate Activation by Piezoelectric-Driven Hydrogel-Encapsulated Z-Scheme Heterojunction for Levofloxacin Degradation

Actualizing energy-efficient and sustainable activation of peroxymonosulfate (PMS) for advanced wastewater treatment remains a persistent challenge. While piezoelectric materials can harness mechanical energy to activate PMS, they often suffer from inefficient carrier separation, limited active sites, and poor recyclability. Here, we introduce a novel piezoelectric-driven approach for PMS activation using a chitosan hydrogel-encapsulated BaTiO₃/MoS₂ Z-scheme heterojunction (denoted as BTO/MS@CSH). The interfacial electric field within the BTO/MS heterojunction provides a strong driving force for electron–hole separation, ensuring a consistent supply of piezo-excited carriers for cleaving the O–O bonds in PMS. The hydrogel encapsulation is conducive to rapid PMS capture and electron transfer via its functional groups and 3D polymer chain spatial structure, further reducing catalyst consumption, preventing metal leaching, and allowing for easy recovery. This integrated system achieves a remarkable 96.1% degradation of levofloxacin (LEV) within 60 min, with a rate constant of 0.0446 min^–1, demonstrating the synergistic interaction between piezoelectric catalysis and PMS activation while enhancing reactive oxygen species (ROS) generation. Ultimately, the synergistic action of various ROS ensures the mineralization of LEV and safe, nontoxic disposal. This study provides insights into the design of advanced piezoelectric catalysts for sustainable environmental remediation.