Enhanced activity of chemically synthesized hybrid graphene oxide/Mn3O4 composite for high performance supercapacitors

Graphical abstract: Advantages of layer-by-layer (LBL) structure built by pseudocapacitive layers and conducting graphene oxide layers in electrochemical performance showing predominant values of energy and power densities (Ragone plot). Highlights: ► Layer by layer assembly of graphene oxide and Mn3O4 layers. ► Porous morphology of GO/Mn3O4 hybrid nano-composite. ► GO/Mn3O4 hybrid composite provides less ESR and IR drop, has good stability. ► GO/Mn3O4 hybrid composite shows high power and energy density. -- Abstract: In this study, we have improved the capacitance of carbon based graphene oxide (GO) and metal oxide based manganese oxide (Mn3O4) thin films by preparing thin films of GO/Mn3O4 composite using simple and inexpensive successive ionic layer adsorption and reaction (SILAR) method. These prepared films are characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDAX) and BET techniques. The XRD analysis reveals the formation of GO, Mn3O4 and GO/Mn3O4 composite thin films and the FTIR studies disclose the characteristic chemical bonding between the respective materials. Furthermore, Raman measurements confirm the formation of GO and GO/Mn3O4 composite thin films. The SEM images demonstrate that the surface structure of GO and Mn3O4 thin films can be easily tuned by forming the composite of GO and Mn3O4 materials leading to excellent processability of a system. The surface area of GO/Mn3O4 composite (94 m2 g−1) is measured by using Brunauer–Emmett–Teller (BET) technique. The supercapacitive behaviors of different electrodes are evaluated using cyclic voltammetry (CV) and galvanostatic charge–discharge techniques in 1 M Na2SO4. The specific capacitance of 344 F g−1 is achieved for GO/Mn3O4 composite electrode at a scan rate of 5 mV s−1. In addition, impedance measurements of the GO, Mn3O4 and GO/Mn3O4 electrodes are executed proposing that the GO/Mn3O4 composite electrodes are promising materials for supercapacitor application