Effects of pyridine-like and pyrrolic-like nitrogen on the photoluminescence blue-shift of nitrogen-doped graphene oxide quantum dots

Materials with tunable photoluminescence (PL) are highly desirable. It can lead to important applications such as photodetectors, bio-imaging, and broadband modulators. In this work, nitrogen-doped graphene oxide quantum dots (NGOQDs) were synthesized by hydrothermal method. The microstructures as well as optical properties of NGOQDs were studied. The as-prepared NGOQDs present tunable PL and exhibit a maximal PL blue-shift of ca. 88 nm compared to that of the graphene oxide quantum dots (GOQDs). The observed PL blue-shift of the NGOQDs is attributed to the high content of pyridine-like and pyrrolic-like nitrogen atoms doping in the NGOQDs. Our proposed mechanism for the PL blue-shift of the NGOQDs is supported by density functional theory (DFT) calculations.

Automated summary

The study successfully synthesized nitrogen-doped graphene oxide quantum dots (NGOQDs) using a hydrothermal method, and investigated their optical properties and microstructures. The NGOQDs showed tunable photoluminescence and exhibited a larger blue-shift compared to graphene oxide quantum dots. The observed blue-shift in NGOQDs was attributed to the higher content of pyridine-like and pyrrolic-like nitrogen atoms doping, supported by density functional theory calculations.