Optical properties of graphene oxide nanosheets prepared by laser ablation in different liquid medium

Introduction: Graphene is a one-atom-thick planar layer of sp2 hybridization carbon atoms which arrange in a hexagonal structure. A perfect single-layered graphene sheet, is a zero band gap semiconductor and not expected to be photoactive or photoluminescent [1]. By contrast, some of the reports show that chemically synthesized Graphene Oxide (GO) exhibits a broad photoluminescence where the electronic structure has been modified [2]. Material and method: Carbon nanoparticles and graphene oxide nanosheets were produced by pulsed laser ablation of a graphite plate in liquid nitrogen, deionized water, and CTAB 0.01 molar. Produced nanostructures were studied using their UV-Vis-NIR, Photoluminescence, and Raman scattering spectrum.Result and Conclusion: Results show that liquid nitrogen is not a capable carrier medium to produce GO sheets and it may be because of lower mobility of its molecules during ablation process. The peak position of the second-order 2D-band in sample 2 emphasizes the formation of few-layer GO sheets. It confirms that the quality of GO in water is not high enough, whereas the quality of produced GO in CTAB is better than other samples. Furthermore, the oxidation of graphene opens up a band gap in the electronic structure in a way that produces PL. Results show that graphene, although intrinsically a zero-gap semimetal, is oxidized in a way that ‎produces PL

Keywords:

Graphene oxide , Pulsed laser ablation , Photoluminescence , Liquid medium