New insight into electrooxidation of graphene into graphene quantum dots

Highlights: • Graphene quantum dots (GQDs) with an average diameter of ca. 52 nm are prepared via electrooxidation of graphene. • GQDs emit strong blue luminescence upon excitation at 365 nm UV light. • GQDs exhibit excitation wavelength-independent photoluminescence behaviour. A previous study reported that graphene quantum dots (GQDs) generated by electrooxidation of graphene had a uniform size of 3–5 nm and exhibit excitation wavelength-dependent photoluminescence (PL). Here, larger GQDs with an average diameter of ca. 52 nm are obtained via using similar method. And their PL show excitation wavelength-independent properties.