ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Controlled synthesis of graphene oxide/alumina nanocomposites using a new dry sol–gel method of synthesis

Agnieszka Maria Jastrzębska, Joanna Jureczko, Joanna Karcz, Antoni Kunicki, Wanda Ziemkowska, and Andrzej Olszyna

Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw, Poland

E-mail: agsolgala@gmail.com

Abstract: The present paper gives new insight into the problem of controlling the morphology of reduced graphene oxide/alumina (RGO/Al₂O₃) nanocomposites. The dry and simplified sol–gel methods of RGO/Al₂O₃ nanocomposite synthesis were compared and the influence of six key synthesis parameters on the morphology of the resulting nanocomposite powders was investigated to optimize the morphology of RGO/Al₂O₃ nanocomposites in terms of reducing the undesired agglomeration of RGO/Al₂O₃ nanocomposite flakes to a significant minority and obtaining the uniform coverage of RGO surface with Al₂O₃ nanoparticles. Our investigations indicate that, despite the high excess of Al₂O₃ used (95 wt%), the lowest RGO/Al₂O₃ flake agglomeration and the formation of a uniform layer composed of Al₂O₃ nanoparticles with the average size of 58 nm occurred only when 5 wt% of graphene oxide was used as a substrate for the deposition of Al₂O₃ nanoparticles together with triethyl aluminium as an Al₂O₃ precursor and dry hexane as the reaction environment. The resulting organic precursor was thermally decomposed at 280 °C for 3 h in air atmosphere (R4 reaction pathway). This was confirmed by the high BET-specific surface area (242.4 m²/g) and the high open porosity (0.7 cm³/g) of the obtained RGO(5 wt%)/Al₂O₃ nanocomposite. This is also the first study with a detailed discussion of the reactions expected to occur during the synthesis of an RGO/Al₂O₃ nanocomposite.

Keywords: Graphene nanocomposites; Graphene oxide; Aluminium oxide; Nanoparticles; Synthesis optimization; Sol–gel reactions

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-016-0040-4

Chemical Papers 71 (3) 579–595 (2017)