Catalytic activity of Cu–cysteine coated on Ti3C2MXene toward peroxymonosulfate activation for carbamazepine degradation

Abstract

The growing prevalence of pharmaceutical pollutants in water bodies poses a significant threat to the environment, underscoring the urgent need for more effective and sustainable methods for removing these pollutants. This study introduces a novel technique for degrading carbamazepine (CBZ), based on a peroxymonosulfate (PMS) oxidation system catalysed by a copper–cysteine/Ti₃C₂MXene composite (Cu–cy/Ti₃C₂MXene), denoted as CCM. CCM was initially prepared by growing Cu–cy nanoparticles on an MXene sheet to make Cu–cy/Ti₃C₂MXene. CCM was then utilized to activate PMS, facilitating the generation of reactive oxygen species necessary for decomposing CBZ. The CCM + PMS system demonstrated a remarkable 98.6% degradation rate of CBZ within 20 min, outperforming the pristine Cu–cy nanoparticles and Ti₃C₂MXene when applied under the same conditions. Furthermore, to examine the vital contribution of reactive oxygen species in the degradation process, experiments focused on quenching reactions and electron paramagnetic resonance (EPR) analysis demonstrated that both radical species, including sulfate radicals (SO₄·⁻) and hydroxyl radicals (·OH), and non-radical species, such as singlet oxygen (¹O₂), were involved in the degradation of CBZ with non-radical species (¹O₂) exerting a predominant role. Notably, the synthesized material showed excellent reusability and stability in multiple cycles of CBZ degradation. These findings highlight the effectiveness of the CCM + PMS system in addressing water pollution issues caused by CBZ.