Hydrothermal Synthesis and Photocatalytic Activity of Mn3O4 Nanoparticles

In this work, Mn3O4 nanoparticles (NPs) were synthesized by hydrothermal method using the precursor manganese acetate and polyvinyl alcohol (PVA) as a as a structure directing agent. The synthesized Mn3O4 NPs were systematically characterized in terms of their morphology, surfaces, as well as their crystalline and photocatalytic activity. Powder X-ray diffraction results confirm the crystalline structure of Mn3O4 with a tetragonal phase. Field emission scanning electron microscopy results revealed a mixed rod-like morphology and rougsurface spherical particle. The energy dispersive X-ray spectra confirm the homogeneity and purity of the Mn3O4 nanostructure. Further, the hydrodynamic diameter of the synthesized Mn3O4 NPs in water was determined using the dynamic light scattering method. The synthesized Mn3O4 sample showed photocatalytic activity towards methylene blue (MB), and the photodecomposition reaction was described as better with pseudo first order than the second order reaction model. This present work suggests that the prepared Mn3O4 nanostructures are promising photocatalysts for the degradation of MB in an aqueous media under natural solar irradiation for long periods of time without adjusting the pH or introducing an oxidant into the reaction mixture.

Automated summary

In this study, Mn3O4 nanoparticles were synthesized using the hydrothermal method and characterized for their morphology, surfaces, crystalline structure, and photocatalytic activity. The results confirmed the crystalline structure of Mn3O4 with a tetragonal phase and revealed a mixed rod-like morphology and rough surface spherical particles. The synthesized Mn3O4 nanoparticles showed photocatalytic activity towards methylene blue in water under natural solar irradiation for long periods of time, without the need for adjusting the pH or introducing an oxidant into the reaction mixture. This study suggests that the prepared Mn3O4 nanostructures have promising applications as photocatalysts for the degradation of organic dyes in aqueous media.