The Production of Cu Nanoparticles on Large Area Graphene by Sputtering and in‐Flight Sintering

We have developed a simple method to synthesize Cu nanoparticles on graphene, which is a composite that is currently investigated for use as biosensors. Firstly, large area graphene (2 × 2 cm2) was prepared by chemical vapor deposition on Cu foils and then transferred onto SiO2 substrates by a transfer process. The Cu nanoparticles were collected on graphene/SiO2 by magnetron sputtering. The presence of graphene was verified by optical microscopy and Raman spectroscopy. The structure of graphene decorated with Cu nanoparticles was determined by scanning and transmission electron microscopy. The results show that the Cu nanoparticles acquire a cubic structure on graphene. Cu nanoparticles were prepared on large area graphene/SiO2 substrates in the gas‐phase by a combination of DC magnetron sputtering and CVD. High‐resolution microscopy studies show that primary particles produced without in‐flight annealing are spherical with a diameter of about 5 nm. The optimum pressure and sputtering‐time parameters have been determined to produce Cu nanoparticles.