High-Quality Monolayer Reduced Graphene Oxide Films via Combined Chemical Reduction and Ethanol-Assisted Defect Restoration

Here, a facile two-step reduction method is introduced to fabricate reduced graphene oxide (RGO) films with remarkable structural qualities. Many attempts are made to fabricate RGO with high structural qualities resembling pristine graphene. However, designing a reduction method to obtain high-quality RGO more productively is highly desirable. To address this matter, in the present work, monolayer graphene oxide films are, at first, chemically reduced using a mixture of hydroiodic acid and trifluoroacetic acid vapor within a few minutes. Second, the films are reduced thermally at 800 degrees C for 30 min with ethanol, to repair the lattice vacancies. Through this method, the authors succeeded in obtaining RGO with high structural quality and electrical properties approaching pristine graphene. Raman spectroscopic results show that these RGO films have a very low I-D/I-G ratio (0.34), a high I-G '/I-G ratio (1.34), and sharp Raman peaks, which attribute to a large distance between defects (21 nm) and large crystallite size (56 nm). Further, these monolayer RGO films have high transparency (90%) and very low sheet resistance (0.46 k omega sq(-1)). The present versatile two-step reduction strategy is considered to provide practical advancements in fabricating RGO with high structural quality, as a means to produce graphene-based electronic devices.