High-Capacitance Hybrid Supercapacitor Based on Multi-Colored Fluorescent Carbon-Dots

Abstract

Multi-colored, water soluble fluorescent carbon nanodots (C-Dots) with quantum yield changing from 4.6 to 18.3% were synthesized in multi-gram using dated cola beverage through a simple thermal synthesis method and implemented as conductive and ion donating supercapacitor component. Various properties of C-Dots, including size, crystal structure, morphology and surface properties along with their Raman and electron paramagnetic resonance spectra were analyzed and compared by means of their fluorescence and electronic properties. α-Manganese Oxide-Polypyrrole (PPy) nanorods decorated with C-Dots were further conducted as anode materials in a supercapacitor. Reduced graphene oxide was used as cathode along with the dicationic bis-imidazolium based ionic liquid in order to enhance the charge transfer and wetting capacity of electrode surfaces. For this purpose, we used octyl-bis(3-methylimidazolium)diiodide (C8H16BImI) synthesized by N-alkylation reaction as liquid ionic membrane electrolyte. Paramagnetic resonance and impedance spectroscopy have been undertaken in order to understand the origin of the performance of hybrid capacitor in more depth. In particular, we obtained high capacitance value (C = 17.3 μF/cm2) which is exceptionally related not only the quality of synthesis but also the choice of electrode and electrolyte materials. Moreover, each component used in the construction of the hybrid supercapacitor is also played a key role to achieve high capacitance value.

Effect of Wall Boundary Layer Thickness on Power Performance of a Recirculation Microbial Fuel Cell

“…The hydrodynamic boundary layer was formed by liquid flow through a flat plate due to the viscosity of liquid particle, and the thickness of flat plate boundary layer thickness, which can be defined as Equation (2) [46]: δ = 5 µx ρV (2) where x is the electrode position of 1 cm (MFC-1), 6 cm (MFC-2), and 9 cm (MFC-3). (Corresponding to the hydrodynamic boundary layer thickness of 1.6, 4.1, and 5 cm [58]), and the schematic diagram of hydrodynamic boundary layer that was applied to MFCs were showed in Figure 5.…”

“…In recent years, the development of renewable energy (solar energy, wind power, bio-energy, and fuel cell) and electric transportation/storage technologies (supercapacitors) has begun to flourish due to the consumption and pollution that is caused by fossil fuels [1][2][3]. Microbial fuel cells (MFCs) are renewable energy technology transducers [4], which has the potential for application in wastewater treatment plants [5,6], electrical devices [7,8], and biosensor [9,10], because it can use bacteria for generating electricity from waste water.…”

Untreated Natural Graphite as a Graphene Source for High-Performance Li-Ion Batteries

“…Among the most studied materials in Li-ion batteries for energy storage are Graphene-based materials [2,3]. The capability of graphene in different energy devices is also being investigated deeply, such as in supercapacitors [4,5], fuel cells [6,7] and solar cells [8,9].…”

Fullerenes: Synthesis and Applications

“…However, poor accessibility of electrolyte to solid surfaces usually results in low capacitance (Genc et al, 2017), thus nanotechnology has opened up new openings via the use of a wide range of carbon based nano materials all in a bid to surmount the aforementioned inadequacies (Yu, Tetard, Zhai, & Thomas, 2015).…”