Temperature-Dependent Optical Properties of Oxidized Graphenes

Abstract

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.

Tunable optical and semiconducting properties of eco-friendly-prepared reduced graphene oxide

“…To further emphasize our eco-friendly approach, previous studies ( Begum et al, 2017 ; Tene et al, 2022b ; Tene et al, 2022c ) have shown that GO can be transformed into rGO using green reducing agents such as citric acid (CA) ( Tene et al, 2023b ). In our current study, we specifically focus on GO reduced using AA.…”

“…Here, we provide a brief description of the synthesis of GO and rGO, which is depicted in Schematic S1. Our prior works and associated applications ( Tene et al, 2020 ; Tene et al, 2022b ; Tene et al, 2023a ; Tene et al, 2023b ) contain more comprehensive information regarding the full synthesis process. Furthermore, for a meaningful comparison with the present work involving other environmentally friendly reducing agents, please refer to Ref.…”

“…Furthermore, for a meaningful comparison with the present work involving other environmentally friendly reducing agents, please refer to Ref. ( Tene et al, 2023b ).…”