Solution synthesis and electrochemical capacitance performance of Mn3O4 polyhedral nanocrystals via thermolysis of a hydrogen-bonded polymer

Hausmannite Mn3O4 polyhedral nanocrystals have been successfully synthesized via a simple solution-based thermolysis route using a three-dimensional hydrogen-bonded polymer as precursor. The as-obtained product was characterized by means of powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Possible formation mechanism of polyhedral nanocrystals was proposed based on the role of organic ligand dissociation from the polymer precursor at elevated temperature. The electrochemical capacitance performance of Mn3O4 electrode was investigated by cyclic voltammetry and galvanostatic charge/discharge measurements. A maximum specific capacitance of 178 F g−1 was obtained for the nanocrystals in a potential range from −0.1 to 0.8 V vs. SCE in a 0.5 M sodium sulfate solution at a current density of 0.2 A g−1.

Research highlights▶ A hydrogen-bonded polymer was used to synthesize Mn3O4 polyhedral nanocrystals. ▶ Ligand plays an important role in the formation of Mn3O4 polyhedral nanocrystals. ▶ Mn3O4 polyhedral nanocrystals displayed electrochemical capacitance performance in 0.5 M Na2SO4 electrolyte.