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

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.