Tailoring the Nonlinear Optical Response of Some Graphene Derivatives by Ultraviolet (UV) Irradiation

Abstract

In the present work the impact of in situ photoreduction, by means of ultraviolet (UV) irradiation, on the nonlinear optical response (NLO) of some graphene oxide (GO), fluorographene (GF), hydrogenated fluorographene (GFH) and graphene (G) dispersions is studied. In situ UV photoreduction allowed for the extended modification of the degree of functionalization (i.e., oxidization, fluorination and hydrogenation), leading to the effective tuning of the corresponding sp2/sp3 hybridization ratios. The nonlinear optical properties of the studied samples prior to and after UV irradiation were determined by means of the Z-scan technique using visible (532 nm), 4 ns laser excitation, and were found to change significantly. More specifically, while GO’s nonlinear optical response increases with irradiation time, GF and GFH present a monotonic decrease. The graphene dispersions’ nonlinear optical response remains unaffected after prolonged UV irradiation for more than an hour. The present findings demonstrate that UV photoreduction can be an effective and simple strategy for tuning the nonlinear optical response of these graphene derivatives in a controllable way, resulting in derivatives with custom-made responses, thus more suitable for different photonic and optoelectronic applications.

Superhydrophobic and Electrochemical Performance of CF2-Modified g-C3N4/Graphene Composite Film Deposited by PECVD

“…Graphene with a two-dimensional nanostructure possesses unique optical, electrical, and mechanical properties, which helps it work as a popular functional material [1][2][3]. The main preparation methods for high-quality graphene are the micro-mechanical stripping method [4], the epitaxial growth method [5], the graphite oxide reduction method [6], and the chemical vapor deposition method [7].…”