Sugar cane bagasse stands as a prevalent and abundant
form of solid
agricultural waste, making it a prime candidate for innovative utilization.
Harnessing its potential, we embarked on a groundbreaking endeavor
to evaluate the sustainability of a molasses-based hydrothermal process
to produce graphene quantum dots (GQDs). This pioneering initiative
promises remarkable environmental benefits and holds immense economic
potential. Embedding crystalline GQDs in activated carbon (AC) boost
electrochemical efficiency by enhancing charge-transfer and ion migration
kinetics. Optical, structural, and morphological evaluations were
used to confirm the formation of GQDs. Transmission electron microscopy
(TEM) investigation showed the size, shape, and fact that GQDs were
monodispersed, and X-ray diffraction and Fourier transform infrared
determined the structure of GQDs. The electrodes with negative (AC)
and positive (AC@GQDs) polarity demonstrate a considerable specific
capacitance of 220 and 265 F g–1, respectively,
when measured at 0.5 A g–1. Additionally, these
electrodes exhibit high-rate capabilities of 165 and 230 F g–1 when measured at 5 A g–1, as determined by galvanostatic
charge–discharge techniques. The supercapacitor device comprising
asymmetric AC//AC@GQDs exhibits a specific capacitance of 118 F g–1. Furthermore, the asymmetric device exhibits exceptional
cycling behavior, with an impressive 92% capacitance retention even
after undergoing 10,000 cycles. This remarkable performance underscores
the immense potential of both the negative and positive electrodes
for real-world supercapacitor applications. Such findings pave the
way for promising advancements in the field and offer exciting prospects
for practical utilization.