KMnO4-Induced Amorphization of ZIF-67 on Plasma Electrolytic Oxidation Coatings for Enhanced Photocatalytic Performance

This study explores the enhancement of photocatalytic activity in Zeolitic Imidazolate Framework-67 (ZIF-67), integrated with plasma electrolytic oxidation (PEO) coatings on an AZ31 magnesium alloy through post-treatment with potassium permanganate (KMnO4). The KMnO4 treatment induces the partial amorphization of ZIF-67, resulting in improved light absorption and the increased availability of catalytic sites. Structural and compositional analyses confirmed the formation of MnOx species and amorphous domains that synergistically contribute to enhanced photocatalytic performance. Under visible light, the treated coatings demonstrated remarkable efficiency, degrading 99.43% of rhodamine B (RhB) dye within just 50 min, an improvement attributed to superior light absorption, enhanced charge separation, and the introduction of additional active sites. These findings establish KMnO4 post-treatment as a transformative approach for optimizing MOF-based coatings, offering a pathway to develop advanced functional coatings with exceptional dye degradation capabilities.