Investigating Efficiency of Glucose-Derived Graphene Quantum Dots in Photocatalysis

Graphene is unique in that it has a zero bandgap, unlike graphene quantum dots. However, the functionalization of graphene allows a significant alteration in its properties. Here, graphene quantum dots (GQDs) were fabricated in an aqueous medium via carbonization, using glucose as a carbon precursor at ambient temperature. The process is environmentally benign and cost-effective with de-ionized water as a solvent and ammonia as a catalyst. The chemical compositional and morphological analysis of GQDs were performed by FTIR and HRTEM, respectively. The as-synthesized GQDs were spherical and showed an absorption peak at 280 nm. Additionally, they exhibit strong emission in the blue region at 350 nm and display excitation wavelength-dependent features. The resulting GQDs have a bandgap of 3.81 eV. The study evaluated the catalytic activity of GQDs under NaBH4-mediated photoreduction and compared their efficiency in degrading the organic rhodamine B dye under visible and UV radations for 16 min. The outcome of the study revealed that GQDs possess exceptional photocatalytic activity.