Review of the Direct Laser Synthesis of Functionalized Graphene and its Application in Sensor Technology

Abstract

Since the breakthrough in fabricating graphene by mechanical exfoliation in 2004, numerous methods have been developed to synthesize high-quality graphene materials on a large scale, including chemical exfoliation, thermolysis, and chemical vapor deposition. Recently, laser thermal treatments have emerged as facile methods for the direct synthesis of functionalized graphene materials, which show potential for use in a wide range of applications. The graphene materials produced by laser-based syntheses are classified by the fabrication method as either laserreduced graphene or laser-induced graphene (LIG). The former is obtained through the chemical reduction of graphene oxide, while the latter utilizes the carbonization of a polymer precursor. In this review, we summarize the mechanisms of laser-assisted graphene syntheses, the structural and chemical functionalization of laser-scribed graphene, and various practical demonstrations of graphene-based materials in the field of mechanical and electrochemical sensors.

All-Optical Diffractive Deep Neural Networks Enabled Laser-Reduced Graphene Oxide Tactile Sensor for Braille Recognition

“…The mechanism of laser reduction of GO is mainly closely related to the photochemical and photothermal effects of the laser. , When the laser irradiates the surface of the thin film, the photothermal and photochemical effects of the laser remove the oxygen-containing functional groups and simultaneously convert sp 3 to sp 2 . , Typically, laser irradiation can reduce GO to a certain extent and improve their electrical conductivity. However, complete reduction depends on the combined effect of several factors, and laser parameters such as power, wavelength, and irradiation time can impact the reduction effect.…”

Laser-scribed graphene for sensors: preparation, modification, applications, and future prospects

“…Compared with the GO film, the ID/IG of graphene oxide after laser reduction is slightly larger than that of the original GO film. The GO reduction mechanism has been reported to be closely related to the photochemical and photothermal effects of the laser 62 . There are two sub-processes in LrGO, namely the direct conversion of sp 3 carbon to sp 2 carbon and the removal of oxygen, both of which involve photochemical and photothermal effects.…”

Recent trends in covalent functionalization of 2D materials

“…Graphene 476–480 and TMDCs 481–483 can be synthesized by laser irradiation by local high-temperature heating from the photothermal effect. When the laser power is sufficiently strong to carbonize the precursor before it reacts with oxygen in the air and burns, the carbon-containing material thermally carbonizes and becomes laser-induced graphene (LIG).…”