SnO2 quantum dots decorated BiOI nanoflowers as a high-performance electrode material for supercapacitor application

The rational design of low-cost electrode materials with superior redox activity and high electrochemical conductivity has attracted extensive interest for next-generation supercapacitors. In this study, SnO2 quantum dot–decorated BiOI nanoflowers (BIOS) were successfully synthesized for application in high-capacity supercapacitors. Various structural, morphological, and electrochemical studies were performed on the synthesized samples. The SnO2 quantum dots (SO) decorated over the BiOI nanostructures exhibited superior electrochemical behavior compared to pure BiOI nanostructures (BIO). The electrochemical performance of the fabricated electrodes was investigated in 3.0 M KOH electrolyte. The BIOS electrode demonstrated an excellent specific capacity of 1285 F.g−1 at a current density of 11 A·g−1, 7.5 times that of the BIO electrode. The increased availability of active sites for ion transfer in possible oxidation/reduction reactions after the decoration of SO over BIO nanostructures may have enhanced the galvanostatic charge–discharge (GCD) characteristics. Despite 3000 GCD cycles, the BIOS electrode still attained better supercapacitive characteristics than the BIO electrode. The findings of this study may assist in designing advanced, cost-effective, and high-performance electrode materials for energy storage applications.