In this paper, enhancement of the nonlinear optical properties of graphene oxide by repairing with palladium nanoparticles is reported. Graphene oxide, palladium nanoparticles, and their nanocomposite are prepared by chemical methods. Structural and optical properties of all the synthesized samples have been investigated. It is shown that palladium nanoparticles repair the graphene oxide sheet by reducing the number of oxygen functional defects and simultaneously increasing the number of sp2 carbon atoms and delocalized π-electrons. Employing the Z-scan technique for measuring the nonlinear optical properties of the samples, it is shown that Pd nanoparticles can considerably enhance the nonlinear refractive index and absorption coefficient of graphene oxide. Enhanced nonlinear optical properties of graphene oxide can open up exciting prospects for its application in different fields. The used nonlocal Z-scan theory for interpreting the nonlinear measurement data indicates that Mie scattering from the spherical nanoparticles dominates their nonlocal optical response.
