Investigating electrochemical properties of iron oxide-carbon nanotube composite for supercapacitor application

Abstract

In this work we are reporting the influence of addition of carbon nanotubes (CNTs) to Fe2O3 nanoparticles on the electrochemical characteristics of prepared composite. Fe2O3-CNT composite were prepared by treating ferricyanide (K3Fe(CN)6), sodium dodecylbenzene sulfonate (SDBS), and commercially procured carbon nanotubes (CNTs) under hydrothermal condition at 150 °C for 20 h. We have varied the concentration of the carbon nanotubes and Fe2O3 to attain a Fe2O3: CNT ratio of 1:1, 1:1.5 and 1:2.5. It was found that for the optimized concentration at 1:1.5, the sample showed the highest pseudo-capacitance which was attributed to the improvement in the conductivity due to added CNT and the optimized concentration of Fe into the composite. Further, the impedance analysis reveals that the sample having the 1.5 ratio gives the highest pseudocapacitance. On the other hand, for 1 and 2.5 ratio the pseudocapacitance is lower due to the low and excess carbon nanotubes, which gives reduced and higher conductivity effect. Thus, the optimized conductivity with the maximum active material gives the highest activity and suitable for supercapacitor application.