Synthesis and optical properties of Zn(II) doped graphene quantum dots: Blue to purple emission

The Graphene Quantum dots (GQDs), fragments of graphene have attracted considerable attention in recent years due to the size, edge effects, quantum confinement and heteroatom doping. The doping of graphene based materials can effectively tune their intrinsic properties, including electronic and optical properties, surface and local chemical reactivity. Herein, we present a comprehensive study of ZnO doped GQDs prepared by a facile hydrothermal method by using ZnO and Graphne Oxide (GO) as a source materials. All the synthesized materials were characterized by UV-Visible Spectroscopy (UV-Vis), Raman Spectroscopy, Fourier Transform Infrared (FT-IR) and Photoluminescence (PL). The morphological characterizations were confirmed by transmission electron microcopy images (TEM). The hydrothermally synthesized material had a size of 5-20 nm by uniform doping of zinc nanoparticles on graphene sheet. The results of PL of Zn(II)-GQDs showed a blue to purple emission with the variation in excitation wavelength from 280nm to 380nm. These doped GQDs were found to be an efficient approach with multicolor emission for biological applications and optoelectronic devices to make the environmental friendly, cost effective and easily scalable.