Modification of structure and optical properties of graphene oxide dots, prepared by laser ablation method

Abstract

Modification of structure, optical and luminescent properties of graphene oxide (GO) by laser ablation at 532 nm during various times was studied. It was shown that after 30 minutes of laser ablation, the average lateral size of GO sheets decreases from 272±120 nm to 62±29 nm. Studies of structural properties by Raman and FTIR spectroscopy and microscopy indicate the reduction and graphitization of GO at laser irradiation times greater than 20 minutes, which leads to an increase in the average crystallite size of sp2 carbon domains and a decrease in the number of GO layers in the resulting particles. The optical density of the resulting GO solutions and the intensity of their fluorescence are also time dependent. After ablation, the GO fluorescence intensity increased by 10, 25, and 36% for 10, 20 and 30 minutes, respectively. In the long-lived luminescence spectrum of GO, a broad emission band was recorded after ablation, whereas for GO before ablation long-lived luminescence was not exhibited.