Solvent dispersible nanocomposite based on Reduced Graphene Oxide in situ decorated with gold nanoparticles

A facile in situ colloidal approach is reported to synthesize a novel hybrid nanocomposite formed of 3,4-dimethylbenzenethiol (DMBT)-capped Au NPs, decorating flakes of 1-pyrene-carboxylic acid (PCA) functionalized Reduced Graphene Oxide (RGO). In the nanocomposite, the Au NPs and RGO sheets are anchored by means of the aromatic PCA linker and the DMBT capping ligand, both ensuring electronic coupling due to particle/RGO and interparticle ?-? interactions, respectively. The short aromatic thiol has been selected to i. yield additional binding sites for the NPs to the PCA-RGO surface, ii. potentially enhance electron conductivity and promote charge transfers, and iii. enable dispersibility in organic solvents. The role of the synthetic parameters on the resulting Au NPs morphology and on their organization onto the PCA-RGO sheets has been comprehensively investigated in order to elucidate the mechanism underlying the in situ NPs formation. Organic dispersions of the PCA-RGO flakes, densely and uniformly decorated with a multilayer network of DMBT-coated Au NPs, 2-3 nm in size, have been achieved, thus overcoming limitations previously reported for similar hybrid materials. The prepared nanostructures are attractive functional platforms for future FETs and (photo)electrochemical (bio)sensors, (photo)catalysis, photodetectors, memory devices and solar cells.