Graphene or carbon nanowalls, graphene sheets, and graphene nanoflakes are other names for vertical graphene (VG), a three-dimensional form of graphene. Compared to conventional horizontally oriented or randomly arranged graphene, the interest in vertically oriented graphene can be attributed to its unique geometry and open three-dimensional lattice, which allows easier access to the graphene edges, higher surface-to-volume ratio, high electrochemical activity, and electrical conductivity. The electrochemical properties of VG can be improved by incorporating nanoparticles that can change the major type of charge carriers, increase the specific surface and prevent the aggregation of graphene sheets. In this paper, we established a process for synthesising VG-based nanocomposites by treating graphene in an acid solution and then decorating the sheets with gold nanoparticles. The vertical graphene obtained by the chemical vapour deposition process on the Si/SiO2 substrate is subjected to a treatment with H2SO4 and HNO3 to improve the wetting capacity. The anchoring of the metallic nanoparticles is carried out through an ex-situ process, which involves 2 stages, in the first part the synthesis of the metallic nanoparticles is performed, and in the second step, the GV substrate is immersed in the gold NPs solution. Gold nanoparticles are obtained using chloroauric acid, as a precursor, and trisodium citrate, as both reducing agent and electrostatic stabilizer of the nanoparticles to avoid agglomeration. Using SEM microscopy, the shape, size, and distribution of metal nanoparticles inside the graphene were evaluated. Spectroscopy was used for the structural analysis, and goniometric studies revealed the wetting and percolation capacity of the obtained materials. The application capacity was demonstrated by cyclic voltammetry.
Acknowledgements: This work was supported by the Core Program within the National Research Development and Innovation Plan 2022-2027, carried out with the support of MCID, project no. 2307 (µNanoEl).