Efficient Blue Luminescent Graphene Quantum Dots and their Photocatalytic Ability Under Visible Light

Graphene Quantum Dots (GQDs) are considered to be a new class of materials with distinctive photoluminescence and low toxic level properties. Herein, we have reported the preparation of GQDs at different pH (pH 5, 8, 10, and 14) from pyrocatechol. UV-Visible absorption and normalized fluorescence spectra were applied to analyze the optical properties of GQDs at different pH. DLS and AFM had been performed to study the mean particle size and the morphology of the GQDs. Further, the photocatalytic behavior of the synthesized GQDs obtained at pH 10 was used in the degradation of dyes viz. Methylene Blue and Methyl Orange under visible-light irradiation. The influence of certain parameters such as pH of the GQD, contact time, a dosage of GQDs, and the kinetic model was demonstrated. The plausible mechanism of degradation of the toxic dyes based on GQDs under visible light illumination was discussed, too.