▎ 摘　　要

It is necessary to broaden the finite band gap of the graphene quantum dots (GQDs) and prepare deep ultraviolet emission GQDs with high luminescence efficiency. In this study, the deep ultraviolet emission ferric passivated GQDs (Fe-GQDs) are successfully prepared. Due to the strong negative inductive effect of Fe, the band gap of the Fe-GQDs was broadened, and the photoluminescence emission wavelength is 275 nm for an excitation at 224 nm with a very high fluorescent quantum yield (phi = 0.63). This is the shortest emission wavelength reported for solution-based inorganic and organic quantum dots. The high efficient ultraviolet emission, as well as the good stability and low in vitro cytotoxicity, may facilitate their applications to carbon-based light-emitting devices and lasers. (C) 2015 Elsevier B.V. All rights reserved.