Facile synthesis and optical properties of nitrogen-doped carbon dots

Among the chemical doping elements, nitrogen atoms play a critical role in tuning the intrinsic properties or exploiting new phenomena of carbonaceous materials. Herein, we report a facile strategy to synthesize nitrogen-doped carbon dots (NCDs) using glutamic acid as the precursor via a one-step thermal conversion process. The as-produced NCDs exhibit bright blue photoluminescence (the quantum yield of ca. 23.2%), and the emission wavelength could be slightly tuned through changing the parameters of the synthesizing process. Interestingly, apart from their superior luminescence characters, unexpected cathodoluminescence (CL) and frequency upconverted emission properties were both observed in the NCDs.