Synthesis and characterization of linear/nonlinear optical properties of graphene oxide and reduced graphene oxide-based zinc oxide nanocomposite
Mohsen Ebrahimi Naghani, Mina Neghabi, Mehdi Zadsar, Hossein Abbastabar Ahangar
Abstract
Abstract In this paper, we aimed to investigate the linear and nonlinear optical properties of GO-ZnO and RGO-ZnO nanocomposites in comparison with pure GO and reduced graphene oxide (RGO). For this purpose, GO, RGO, GO-ZnO, and RGO-ZnO were synthesized and characterized by Fourier transform infrared (FT-IR), Ultraviolet–Visible (UV–Vis) absorption, X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). XRD and EDX analysis indicated the reduction of GO as well as the successful synthesis of GO-ZnO and RGO-ZnO nanocomposites. The FT-IR spectroscopy showed that absorption bands were at 3340 cm −1 , 1630 cm −1 , 1730 cm −1 and 480 cm −1 related to OH, C=C, C=O, and Zn–O stretching vibrations, respectively. The direct band gaps of GO, RGO, GO-ZnO and RGO-ZnO from UV–Vis spectra were at 3.36, 3.18, 3.63 and 3.25 eV, sequentially. Moreover, the third-order nonlinear optical properties were investigated using a z-scan technique with Nd: YAG laser (532 nm, 70 mW). It can be seen that the nonlinear absorption coefficient value $$(\upbeta )$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>β</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> increased from 5.3 × 10 –4 (GO) to 8.4 × 10 –3 cm/W (RGO-ZnO). In addition, nonlinear refractive index (n 2 ) of the GO, RGO, GO-ZnO, and RGO-ZnO was obtained as 10.9 × 10 –10 , 14.3 × 10 –10 , 22.9 × 10 –10 , and 31.9 × 10 –10 cm 2 /W respectively.