Hydrothermal synthesis of novel Mn3O4 nano-octahedrons with enhanced supercapacitors performances

Abstract

Uniform and single-crystalline Mn₃O₄ nano-octahedrons have been successfully synthesized by a simple ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) assisted hydrothermal route. The octahedron structures exhibit a high geometric symmetry with smooth surfaces and the mean side length of square base of octahedrons is ∼160 nm. The structure is reckoned to provide superior functional properties and the nano-size achieved in the present work is noted to further facilitate the material property enhancement. The formation process was proposed to begin with a “dissolution–recrystallization” which is followed by an “Ostwald ripening” mechanism. The Mn₃O₄ nano-octahedrons exhibited an enhanced specific capacitance of 322 F g⁻¹ compared with the truncated octahedrons with specific capacitances of 244 F g⁻¹, making them a promising electrode material for supercapacitors.