Tene Talia, Vinueza-Naranjo Paola G, Cevallos Yesenia, Arias Arias Fabian, La Pietra Matteo, Scarcello Andrea, Salazar Yolenny Cruz, Polanco Melvin Arias, Straface Salvatore, Vacacela Gomez Cristian, Caputi Lorenzo S, Bellucci Stefano
Department of Chemistry, Universidad Técnica Particular de Loja, Loja 110160, Ecuador.
College of Engineering, Universidad Nacional de Chimborazo, Riobamba 060108, Ecuador.
Nanomaterials (Basel). 2023 Aug 7;13(15):2263. doi: 10.3390/nano13152263.
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.
在本研究中，我们探究了改变重要的合成相关参数如何影响和控制氧化石墨烯（GO）和还原氧化石墨烯（rGO）的光学特性。这些参数包括在两个不同温度下的干燥时间和还原时间。通过分析这些因素，我们了解了它们对光学跃迁、光学带隙、吸收系数和吸收光谱宽度的影响。相应地，GO的光学带隙约为4 eV，通过还原过程降低至1.9 eV。GO和rGO在可见光谱中均表现出更大的吸收，这提高了光子捕获能力并提升了能量转换应用中的效率。此外，我们的结果表明，GO和rGO的吸收系数高于先前报道的剥离石墨烯分散体的吸收系数。GO和rGO中的缺陷以及官能团的存在是吸收增加的主要原因。进行了多项测量，包括光谱和形态学研究，以进一步支持我们的发现。
