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

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.

Topics

• nanoparticle
• Deposition
• nanocomposite
• impedance spectroscopy
• surface
• aluminium
• porosity