Enhanced supercapacitive performance of binary cooperative complementary Co(OH)2/Mn3O4 nanomaterials directly synthesized through ion diffusion method controlled by ion exchange membrane

Binary cooperative complementary Co(OH)2/Mn3O4 nanocomposites were directly synthesized through an ion diffusion method controlled by ion exchange membrane without using any oxidizing agent, template or calcination. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) isotherm were carried out to characterize the morphology, structure, chemical composition, specific surface area and pore size distribution of the as-prepared nanomaterials. The results show that the suitable Co2+ content in Co(OH)2/Mn3O4 nanocomposites can improve the agglomeration of samples, increase the surface area of samples and form more mesoporous structures. The supercapacitive performance of Mn3O4 and Co(OH)2/Mn3O4 samples have been investigated by cyclic voltammograms (CV), galvanostatic charge-discharge and impedance spectroscopy tests. When Co and Mn molar ratios in the nanocomposites were 1: 9, the as-prepared electrode exhibit a highest specific capacitance of 214 F g−1 at a current density of 0.5 A g−1, which is 118% higher than that of pure Mn3O4. In addition, the results verify that there is a synergistic effect between Co(OH)2 and Mn3O4 nanoparticles, which plays a significant role in enhancing the electrochemical performance of nano Mn3O4.