Electrochemically Exfoliated Graphene-Like Nanosheets for Use in Ceramic Nanocomposites

• Published in: Materials Vol. 13; no. 11; p. 2656
• Main Authors: Poyato, Rosalía, Verdugo, Reyes, Muñoz-Ferreiro, Carmen, Gallardo-López, Ángela
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 11.06.2020; MDPI
• Subjects: 3YTZP; Ball milling; Butanol; Ceramic matrix composites; ceramic nanocomposites; Ceramics; Chemical vapor deposition; Composite materials; Defects; Diamond pyramid hardness; electrochemical exfoliation method; Electrolytes; Exfoliation; Fillers; Graphene; Graphite; Methods; Microscopy; Nanocomposites; Nanosheets; planetary ball milling; Plasma sintering; Raman spectroscopy; Spark plasma sintering; Spectrum analysis; SPS; Tetragonal zirconia; Thickness; Yttrium oxide; Zirconium dioxide; United Kingdom > UK; Japan; Germany; Spain; Vickers indentations; SPS; ceramic nanocomposites; electron microscopy; 3YTZP; Raman spectroscopy; planetary ball milling; electrochemical exfoliation method; graphene
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma13112656

In this work, the synthesis of graphene-like nanosheets (GNS) by an electrochemical exfoliation method, their microstructural characterization and their performance as fillers in a ceramic matrix composite have been assessed. To fabricate the composites, 3 mol % yttria tetragonal zirconia (3YTZP) powders with 1 vol % GNS were processed by planetary ball milling in tert-butanol to enhance the GNS distribution throughout the matrix, and densified by spark plasma sintering (SPS). According to a thorough Raman analysis and SEM observations, the electrochemically exfoliated GNS possessed less than 10 graphene layers and a lateral size lower than 1 μm. However, they contained amorphous carbon and vacancy-like defects. In contrast the GNS in the sintered composite exhibited enhanced quality with a lower number of defects, and they were wavy, semi-transparent and with very low thickness. The obtained nanocomposite was fully dense with a homogeneous distribution of GNS into the matrix. The Vickers hardness of the nanocomposite showed similar values to those of a monolithic 3YTZP ceramic sintered in the same conditions, and to the reported ones for a 3YTZP composite with the same content of commercial graphene nanosheets.