Synthesis of TiVAlC MAX phase for degradation of pharmaceutical pollutants by visible-light-promoted catalytic activation of peroxymonosulfate

The development of high-performance MAX phase catalysts for activating sulfate radical-based (SO₄ ⁻) advanced oxidation processes is necessary for removing emerging pharmaceutical contaminants from water. In this study, the TiVAlC MAX phase is synthesized using the reactive sintering method, and its efficacy in activating peroxymonosulfate (PMS) under visible light (Vis) is investigated for the efficient degradation of rifampicin (RIF). The hexagonal crystalline structure of the MAX phase catalyst was verified by X-ray diffraction (XRD). Additionally, scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) images both revealed a layered morphology consistent with the structural properties expected for MAX phase materials. Under optimized conditions, the TiVAlC MAX phase (1 g L⁻¹) efficiently activated PMS (0.1 mmol L⁻¹) under Vis, achieving an 81 % degradation efficiency (DE) of RIF in 90 min. Gas chromatography-mass spectroscopy (GC–MS) identified potential RIF degradation intermediates and suggested a plausible pathway. Overall, this study offers a novel perspective on the catalytic activation of PMS for the degradation of organic pollutants.