Effective activation of peroxymonosulfate by CoCr-LDH for removing organic contaminants in water: from lab-scale to practical applications

In this study, CoCr layered double hydroxide material (CoCr-LDH) was prepared and used as an effective catalyst for peroxymonosulfate (PMS) activation to degrade organics in water. The prepared CoCr-LDH material had a crystalline structure and relatively porous structure, as determined by various surface analyses. In Rhodamine B (RhB) removal, the most outstanding PMS activation ability belongs to the material with a Co:Cr molar ratio of 2:1. The removal of RhB follows pseudo-first-order kinetics (R2 > 0.99) with an activation energy of 38.23 kJ/mol and efficiency of 98 after 7 min of treatment, and the total organic carbon of the solution reduced 47.2 after 10 min. The activation and oxidation mechanisms were proposed and the RhB degradation pathways were suggested with the key contribution of O2•- and 1O2. Notably, CoCr-LDH can activate PMS over a wide pH range of 4 – 9, and apply to a wide range of organic pollutants and aqueous environments. The material has high stability and good recovery, which can be reused for 5 cycles with a stable efficiency of above 88, suggesting a high potential for practical recalcitrant water treatment via PMS activation by heterogeneous catalysts. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.