Improved Electrochemical Performance of Fe₃O₄ Nanoparticles Decorated Activated Carbon Supercapacitor Electrodes

Metal oxide decorated activated carbon (AC) composites exhibit excellent electrochemical property and which is potential for energy storage and catalytic applications. Here, we report the synthesis of iron oxide (Fe₃O₄) anchored AC composite for supercapacitor (SC) electrode. The citrate-stabilized Fe₃O₄ aqueous dispersion (5 mg/mL) of various concentration was utilized for the functionalization of commercial AC and the sample prepared using 50 mL Fe₃O₄ aqueous dispersion in 2 g of AC (AC-50Fe) displayed better surface morphology with comparable surface area and porosity. Moreover, the sample AC-50Fe showed excellent electrochemical performance with a maximum specific capacitance value 131 Fg⁻¹ and cyclic stability ∼105% after 10 000 charge/discharge cycles, which is much higher than the bare AC (77 Fg⁻¹) and AC-25Fe (91 Fg⁻¹) electrodes. Thus, the optimum amount of Fe₃O₄ in AC can effectively enhance the SC performance of the electrode by supplying additional pseudocapacitance along with the electric double-layer capacitance of AC.