Facile synthesis of three-dimensional Mn3O4 hierarchical microstructures and their application in the degradation of methylene blue

A simple and effective route has been developed to synthesize a three-dimensional (3D) Mn3O4 hierarchical architecture, which shows a flower-like morphology and is composed of Mn3O4 nanosheets. Two experimental parameters, hydrothermal temperature and NaOH addition speed, were revealed to have critical effects on the formation of the morphology. Furthermore, these Mn3O4 materials were successfully applied to degrade the organic pollutants in water. Compared with Mn3O4 nanoparticles and nanorods, 3D flower-like Mn3O4 nanostructures are found to most heavily enhance the MB degradation efficiency of the UV/H2O2 advanced oxidation process (AOP), which comes from their high BET surface area and good absorption ability.