One-Step Preparation of Green Fluorescent Graphene Quantum Dots from Petroleum Asphalt

Inherently benefiting from the natural nanosize graphene-structure in raw asphalt material. Asphalt-derived graphene quantum dots ( GQDs ) are prepared through, a facile route, one-step chemical oxidation of cheap petroleum asphalt. The as-prepared GQD sample may be well dissolved in water with a good homogeneous size at an average diameter of 2.44 nm, luminescing bright green light by excitation of 365 nm with a high quantum yield up to 16.13%. Furthermore, they are much smaller and thinner than most of the reported GQDs, presenting excellent fluorescent properties, such as excitation-tuned photoluminescence and good resistance to photobleaching. They are much smaller and thinner than most of the reported GQDs