The demand for nanocomposites (NCs) of graphene and magnetite materials decorated
with gold nanoparticles is increasing on account of their applications in science and
technology. First, graphene oxide (GO) was made with the pulsed laser ablation
technique in liquid (PLAL) and then loaded with magnetite (Fe₃O₄) that was prepared by
the same technique to form Fe₃O₄/GO nanocomposite (NCs). The Au/Fe₃O₄ NCs were
also synthesized and added by volume ratio to the GO solution to form Au/Fe₃O₄/GO
NCs. We investigated the functional groups in the three samples using Fourier transform
infrared spectroscopy (FTIR). We measured the optical absorption spectra of the samples
using UV-visible light. From these optical spectra, we calculated the optical conductivity
(σ), absorption coefficient (α), and other related optical properties. We improved the
optical absorption and other optical parameters while decreasing the band gap (Eg) from
4.1 eV to 3 eV for the three samples. These materials are suitable for photonic
applications, drug delivery applications, and water treatment applications.