Facile template synthesis of dumbbell-like Mn2O3 with oxygen vacancies for efficient degradation of organic pollutants by activating peroxymonosulfate

Abstract

In this work, novel dumbbell-like Mn₂O₃ was prepared using a low-cost and environmentally friendly template (gelatin) and applied to activate peroxymonosulfate (PMS) for pollutant degradation. The characterization results showed that dumbbell-like microstructures were formed by the self-assembly of tiny nanoparticles. Mn₂O₃-G (gelatin as the template) as a heterogeneous catalyst for PMS activation could effectively degrade various pollutants and exhibited an excellent degradation rate of rhodamine B (0.2333 min⁻¹, in 30 min) for PMS activation compared to Mn₂O₃-C (carboxymethyl cellulose as the template), Mn₂O₃-N (without a template), and MnO₂. The superior catalytic performance of Mn₂O₃-G was ascribed to its high oxygen vacancy content. The radical scavenging and EPR experiments revealed that SO₄˙⁻, OH˙, O₂˙⁻, and ¹O₂ were identified as reactive species generated from PMS activation. The oxygen vacancies participated in the generation of the reactive species. Thus, a facile and environmentally friendly method is provided for the synthesis of dumbbell-like Mn₂O₃ as a high-efficiency catalyst for PMS activation. Furthermore, this study shows a new mechanistic insight into PMS activation on Mn₂O₃.