Effect of Enhancement in Surface Area of Sn‐Doped Cobalt Oxide Nanoflakes for Supercapacitor Application

The simple and cost‐effective co‐precipitation method is used for the synthesis of pure Co3O4 and 5% Sn‐doped Co3O4 nanoflakes. Crystallographic parameters, chemical composition, morphological properties, optical properties, and surface area are analyzed using X‐ray diffraction data (XRD), Fourier transform infrared spectroscopy (FT‐IR), Raman analysis, UV–vis, field emission scanning microscopy, energy‐dispersive X‐ray analysis, and Brunauer–Emmett–Teller (BET), respectively. By using cyclic voltammetry and electrochemical impedance spectroscopy in a 2 m KOH electrolyte, the electrochemical characteristics of both pure and 5% Sn‐doped Co3O4 are verified. The sample results show that the presence of Sn2+ has an impact on surface area, band gap, specific capacitance, and electrochemical performance of Co3O4. According to XRD data, synthetic material has a cubic structure. The surface area of the sample is scrutinized using BET which exhibits a higher surface area of 1084.998 m2 g−1 than pure Co3O4 (92.842 m2 g−1) demonstrating that enhancement in surface area as dopant concentration increases. It is observed that porous 5% Sn‐doped Co3O4 nanoflakes has the higher specific capacitance, i.e., 203.6 F g−1 with a high surface area. It is well noticed that drastic change in specific capacitance with 5% Sn doping. These observations and experiments reveal that designed electrode is a promising candidate for supercapacitor application.