ZrO2-supported LaCo0.5Cu0.5O3 composites for enhanced peroxymonosulfate activation and efficient degradation of ibuprofen

Abstract

The tight packing of perovskite particles and secondary pollution limit their peroxymonosulfate (PMS) activation efficiency for water treatment. To address this, an eco-friendly and stable LaCo_0.5Cu_0.5O₃/ZrO₂ (LCCZ) catalyst is synthesized via a sol–gel method. Cu is introduced into the B-site of LaCoO₃ to form LaCo_0.5Cu_0.5O₃ (LaCoCu55) and then supported on ZrO₂. Characterization results confirmed the successful synthesis and dispersion of catalyst. Cu doping promoted Co³⁺/Co²⁺ and Cu²⁺/Cu⁺ redox cycles, while the ZrO₂ support enhanced active site exposure. Under optimized conditions (25 °C, 20 mg L⁻¹ ibuprofen (IBU), 0.1 g L⁻¹ LCCZ, 0.75 mM PMS, pH 7), IBU was completely degraded within 30 min. The catalyst exhibited good recyclability with minimal Co leaching (0.522 mg L⁻¹). After modification to form LCCZ, the enhanced redox cycling between Cu and Co ions, coupled with improved accessibility of active sites to PMS facilitated by the ZrO₂ support, synergistically activated PMS to generate substantial amounts of reactive species including ¹O₂ and ˙SO₄⁻. IBU degrades via ¹O₂ and ˙SO₄⁻-mediated oxidation, forming benzene-ring intermediates before mineralization to CO₂ and H₂O. This work guides perovskite catalyst design for IBU wastewater treatment by PMS activation.