X-ray synthesis of noble metal nanoparticles onto 2D and 3D graphene oxide supports

Abstract

Gold (Au), Palladium (Pd), and Ruthenium (Ru) nanoparticles were synthesized onto 2D and 3D graphene oxide using X-ray induced synthesis. Absorbed doses of ~20 kGy produced Pd and Au nanoparticles of ~5 nm and ~17 nm in size, respectively. Higher absorbed doses such as 60 kGy generated Ru nanoparticles with an average size of ~3 nm. CT-scan imaging confirmed metal particle formation inside the 3D graphene oxide supports, an advantage of X-ray induced synthesis over conventional approaches. The catalytic activity of Ru/GO monoliths, the smallest nanoparticles produced on monoliths, was tested through the olefination of alkyl acrylates. Results showed the high catalytic activity of the heterogeneous Ru catalysts structures similar to the homogeneous catalysis reported in the literature. Overall, this work demonstrates that X-ray assisted synthesis is a method that allows for nanoparticle formation at mild conditions of room temperature and pressure, in the absence of harsh chemicals in aqueous media suitable to fabricate catalysts in 2D and 3D carbon supports.