Temperature-Dependent Optical Properties of Oxidized Graphenes

In this study, we investigate how changing important synthesis-related parameters can affect and control the optical characteristics of graphene oxide (GO) and reduced graphene oxide (rGO). These parameters include drying time and reduction time at two different temperatures. We obtain an understanding of their impact on optical transitions, optical bandgap, absorption coefficient, and absorbance spectrum width by analyzing these factors. Accordingly, GO has an optical bandgap of about 4 eV, which is decreased by the reduction process to 1.9 eV. Both GO and rGO display greater absorption in the visible spectrum, which improves photon capture and boosts efficiency in energy conversion applications. Additionally, our results show that GO and rGO have higher absorption coefficients than those previously reported for dispersions of exfoliated graphene. Defects in GO and rGO, as well as the presence of functional oxygen groups, are the main contributors to this increased absorption. Several measurements are carried out, including spectroscopic and morphological studies, to further support our findings.

Automated summary

This study investigates the influence of changing important synthesis-related parameters on the optical characteristics of graphene oxide (GO) and reduced graphene oxide (rGO). The impact of drying time and reduction time at two different temperatures on optical transitions, optical bandgap, absorption coefficient, and absorbance spectrum width is analyzed. GO has a bandgap of approximately 4 eV, which is reduced to 1.9 eV through the reduction process. Both GO and rGO exhibit enhanced absorption in the visible spectrum, leading to improved photon capture and increased efficiency in energy conversion applications. The higher absorption coefficients of GO and rGO are attributed to defects and functional oxygen groups. Spectroscopic and morphological studies provide further support for these findings.