Synthesis and Characterization of EG/Au Composites via Thermal Exfoliation of Graphite Intercalation Compounds with Tetrachloroauric Acid
Year: 2025
Type: article
Abstract: This study demonstrates a novel route to synthesize gold-decorated exfoliated graphite (EG) through graphite intercalation compounds (GICs) with tetrachloroauric acid (HAuCl4). We aimed to develop a scalable method for producing EG/Au composites with controlled nanoparticle morphology by investigating the effects of precursor chemistry and thermal expansion conditions. II-stage GIC–HAuCl4 (average gross-composition: C23HAuCl4; intercalate layer thickness di = 6.85 Å) was prepared via an exchange reaction of HAuCl4 with graphite nitrate. Interaction of this GIC with liquid methylamine yielded an occlusive complex, where methylamine-bound HAuCl4 occupies both interlayer and intercrystalline spaces in the graphite matrix. Methylamine treatment of GIC reduces the onset temperature of exfoliation by ≈100 °C and enhances the expansion efficiency, yielding EG with a low bulk density range of 4–6 g/L when processed at 900 °C in air or nitrogen. Thermal exfoliation of these GICs yielded EG decorated with gold nanoparticles, exhibiting a broad size distribution from a few nanometers to several hundred nanometers, as confirmed by electron microscopy. An X-ray diffraction analysis identified the coexistence of crystalline gold and hexagonal graphite phases, with no detectable impurity phases.
Source: Nanomaterials
DOI: 10.3390/nano15171363
Authors: Aleksandr D. Muravev, Andrei V. Ivanov, Vladimir A. Mukhanov, Boris A. Kulnitskiy, Natalia V. Maksimova, Victor V. Avdeev
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,896
OpenAlex ID: W4413991319