Laser Reduced Graphene Oxide for Sensor Applications

Reduced graphene oxide (rGO) is made through the reduction of graphene oxide (GO), which involves decomposition and the removal of oxygenated functional groups. In general, the quality of the rGO is not as high as that of pristine graphene because of incomplete reduction, defects, and chemical residue involved in the reduction process. Laser reduction fabrication techniques have the advantage of being simple, single-step, precise, chemical-free, and low temperature processing compared with other reduction methods. The goal of this research is to create rGO membranes using a CO₂ laser system that can be used as electrodes in micro supercapacitors and humidity sensors. Quality rGO membranes have a high conductivity and are very sensitive to moisture and this is achieved by fully reducing the layers of GO in a specific region. The three main laser parameters; power, focal length and frequency were controlled to achieve the best reduction effect. The membranes were examined and characterized using SEM to study the structural changes, Raman spectroscopy and X-ray diffraction analysis to study the chemical composition, and a four point probe impedance test to determine the electrical properties of the membranes. This study will provide a means of reference for the process by which GO laser-induced reduction can be optimized.