Synthesis and electrochemical properties of Mn3O4 nanocrystals with controlled morphologies grown from compact ion layers

Abstract

Different morphologies of Mn₃O₄ nanocrystals including rod-like, plate-like, and round nanoparticles were successfully prepared by a simple one-step process combining electrodeposition and precipitation, directly growing on Ti substrates without using templates or surfactants. In our system, precursor concentration, alkaline medium (LiOH) as a precipitant and the reaction time play important roles in the microstructure evolution of the Mn₃O₄ nanocrystal morphologies. The shape-controlled Mn₃O₄ nanoplates exhibit a maximum specific capacitance of 211 F g⁻¹ at 2 mV s⁻¹ in 1 M Na₂SO₄ for ultracapacitors.