Two-step synthesis of well-ordered layered graphite oxide with high oxidation degree
| Autor: | Piotr Krawczyk, Patryk Florczak, Zuzanna Kabacińska, Tomasz Buchwald, Barbara Peplińska, Bartosz Gurzęda, Ahmed Subrati, Stefan Jurga, L. Smardz |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
General Physics and Astronomy Graphite oxide 02 engineering and technology Electrolyte 010402 general chemistry 01 natural sciences Ion law.invention chemistry.chemical_compound law Acetone Graphite Graphene Surfaces and Interfaces General Chemistry Epoxy 021001 nanoscience & nanotechnology Condensed Matter Physics Exfoliation joint 0104 chemical sciences Surfaces Coatings and Films chemistry Chemical engineering visual_art visual_art.visual_art_medium 0210 nano-technology |
| Zdroj: | Applied Surface Science. 507:145049 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2019.145049 |
| Popis: | Chemical oxidation of graphite by strong oxidant in strong acid medium produces graphite oxide (GO) with a plausible oxidation degree, however the precursor is susceptible to exfoliation and structural deformations. In this work, we present a two-step preparation method of highly oxidized GO flakes with well-ordered layered structure. Firstly, graphite was electrooxidized in HClO4 electrolyte yielding electrochemically gathered graphite oxide (EGO). Next, EGO was chemically overoxidized by modified Hummers method to prepare overoxidized electrochemically gathered graphite oxide (OEGO). Due to the increased interlayer distances of EGO, MnO3+ ions are able to penetrate the interlayer spaces and oxidize the unreacted graphitic domains. Hence, the synthesized OEGO is characterized by minor structure deformation and high oxidation degree. In case of our investigations most of well-ordered layered domains have been preserved, in contrast to the GO obtained directly from graphite. It is also noted that the overoxidation of EGO mainly results in formation of hydroxyl and epoxy groups. Additionally, rinsing OEGO with acetone helps prevent the tearing of oxidized graphene layers by O2 evolution arising from the reaction of H2O2 with MnO2 precipitated on the surface of water-washed samples. |
| Databáze: | OpenAIRE |
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