Environmentally Friendly Supercapacitor Based on Carbon Dots from Durian Peel as an Electrode

Carbon dots (CDs) are novel carbon-based nanomaterials with attractive optical and electronic properties and have become a focal point for tailoring electrochemical performances of energy storage devices. In this work, a pyrolysis method was developed for producing carbon dots from durian peel waste. The carbon dots exhibited blue fluorescence with a quantum yield of 11% and an average size of about 10 nm. Carbon dot-reinforced activated carbon (AC) was used to construct a composite electrode using poly (vinylidene fluoride) as a binder. From cyclic voltamogram, AC/CD composite electrode exhibited a 1.4 fold increase in the specific capacitance (about 60 F g -1 ), compared to that of the pure AC electrode (43 F g -1 ). This capacitance improvement is possibly due to the introduction of high surface-area carbon dots and pseudocapacitive behaviors offered by surface functional groups of carbon dots. These results indicate that carbon dots are effective dopants for improving the electrode properties and subsequently the supercapacitor performances. Converting durian peel waste into functional nanomaterials is also attractive from the various perspectives, offering a strategy that can be potentially applied for many other biomasses.