Study of laser-induced graphene oxide (GO) reduction for electrochemical applications

GO is a single-layer carbon-graphene sheet with oxygen-containing functional groups (OFG) that has electrical insulation and hydrophilic properties. The reduction process of GO involves the removal of OFG, which increases the conductivity and reduces the hydrophilicity. A variety of methods can be used to reduce GO, including thermal, radiation, chemical, electrochemical, and bacterial degradation methods. However, reduced graphene oxide (rGO) has limitations compared to raw graphene due to incomplete reduction and chemical residues. Laser induced Reduction GO (LrGO) has the advantages of repeatability, speed, low cost and automation.

A study by Trusovas et al. It was found that a laser power of 50 mW and a scanning speed of 30 mm/s produced the best reduction results, while Dhrubajyoti et al. According to reports, a laser power of 30 W and a scanning speed of 10 mm/s completely restored the 15 μm GO film. However, the relationship between laser parameters and LrGO mass remains unclear. Furthermore, due to the partial removal of OFG, LrGO is sensitive to water molecules.

The aim of this study was to optimize the laser parameters to achieve a minimum O/C ratio and to explore the surface morphology and composition of rGO by scanning electron microscopy (SEM) imaging. The effect of humidity on the surface impedance of the rGO electrode and potential sensor applications will also be evaluated. Future research will focus on applying advanced gold nanoparticles to improve sensitivity.

The GO film was reduced by CO2 laser engraving machine under ambient conditions. The surface morphology and elemental analysis of the prepared GO and LrGO were characterized by SEM and energy dispersion spectroscopy (EDS). Electrochemical impedance spectroscopy (EIS) was used to measure the AC impedance of the LrGO electrode in the frequency range of 1 HZ-0.1 MHz. The response of electrical impedance to ambient humidity is also studied.

The results show that the surface of GO film is wrinkled due to the "brick" stacking of GO sheets. Laser induced reduction results in incomplete and uneven reduction. The optimal LrGO structure is obtained by optimizing the laser parameters. Further analysis confirmed the reduction and determined the resistance measurements.

In conclusion, laser-induced GO reduction shows promise for electrochemical applications. The study provides insights into the optimization of laser parameters and the surface characteristics of LrGO.

Source: Laser Network