GRAPHENE NANOSHEETS SYNTHESIZED IN MICROWAVE PLASMA AND LIQUID EXFOLIATED GRAPHENE: STRUCTURAL CHARACTERIZATION STUDY
| Authors | |
|---|---|
| Year of publication | 2019 |
| Type | Article in Proceedings |
| Conference | NANOCON 2018 Conference Proceedings, Peer Reviewed |
| MU Faculty or unit | |
| Citation | |
| Web | https://www.nanocon.eu/en/ |
| Keywords | Graphene; electrochemistry; sensor; microwave plasma |
| Attached files | |
| Description | Graphene based nanomaterials produced by liquid exfoliation techniques and microwave plasma decomposition of ethanol were studied by scanning electron microscopy (SEM), Raman spectroscopy and XRay powder diffraction (XRD). Graphene oxide (GO) and reduced graphene oxide (r-GO) prepared by liquid exfoliation technique consisted of several types of structures - thin flakes with thickness of 10-15 nm and lateral dimensions of several micrometers and graphite like structures, 100 mikrometer in size, with not fully exfoliated graphene layers. The graphene nanosheets prepared in microwave plasma torch (MWGNs) were several nm thick and rectangular in shape with size of several hundred nanometers. Contamination by elements S, Mn and K was detected by EDX analysis in both GO and r-GO samples. Similarly, Fe was detected in MWGNs. This contamination was caused by synthesis process in all cases. The Raman spectroscopy analysis showed presence of D (1360 cm-1] and G (1580 cm-1) band and second order 2D (2690 cm-1) and D+G (2920 cm-1) in the measured spectra. The ID/IG intensity ratio was 2.2 and 2.5 for GO and r-GO samples, respectively. The graphene nanosheets Raman spectra exhibited ID/IG ratio of 0.5 and high intensity 2D peak at 2690 cm-1. XRD analysis revealed graphite like structure, graphite peak (002), of all samples and presence of contamination (Fe, intercalation compounds) in agreement with EDX analysis results. XPS analysis confirmed results of XRD and Raman analysis and sp2/sp3 ratio of carbon C1s peak was increasing with decreasing ID/IG intensity ratio. |
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