Preparation of platinum nanoparticles using a continuous-flow precision synthesis system

Platinum nanoparticles (PtNPs) were prepared using a continuous-flow precision synthesis system with hydrogen hexachloroplatinate(IV) hexahydrate and methanol as the metal source and reductant, respectively. The effects of the synthesis conditions, including the reaction temperature and flow tube length, on the size, morphology, and yield of PtNPs were investigated. The X-ray diffraction patterns of the obtained samples revealed the formation of Pt metal crystallites. Transmission electron microscopy suggested that the particle size and morphology of the PtNPs did not change when the reaction temperature and flow tube length were varied, and the PtNPs were spherical with a diameter of ∼3 nm. Conversely, the yield increased considerably with increasing reaction temperature and flow tube length, and the sample prepared using a 5-m flow tube at 140 °C was ∼51 %. Thus, this system can continuously synthesize PtNPs within a few minutes.