Efficient decoration of graphene oxide with a narrow size distribution of noble metal nanoparticles: Green reduction and integration into a thermoelastic composite

We have developed a significantly enhanced method for the effective and homogeneous decoration of graphene oxide (GO) and reduced graphene oxide (r-GO) flakes with gold (Au) and platinum (Pt) nanoparticles. This method involves the direct nucleation of nanoparticles on the surface of dispersed GO through a single-step reaction. By carefully controlling the stepwise introduction of gold and platinum complexes at elevated temperatures, without additional reducing agents, we successfully achieved a homogeneous distribution of Au and Pt nanoparticles, ∼ 20 nm and ∼ 3 nm in size, densely covering the GO sheets. The decoration yield in a mass ratio between Au and GO was up to 20 %. Reduced GO with attached gold and platinum nanoparticles was obtained using ascorbic acid as a reducing agent. Finally, we embedded Au-decorated r-GO in polydimethylsiloxane (PDMS) to form a composite. We show how this stable hybrid material composite can be spin-coated to form a thin thermoelastic film on a flexible substrate, enabling promising photoacoustic properties that could be exploited further in biomedical applications.