Simple, green, and low-temperature method for preparation of palladium nanoparticles with controllable sizes and their characterizations

Palladium nanoparticles (PdNPs) are gaining great interest owing to their excellent physicochemical properties and their wide range of applications. Nanoparticles’ size directly affects the properties and potential applications of PdNPs. Here, we reported a scalable, efficient, green, and one-step method to synthesize PdNPs with controllable sizes. In that, biocompatible polymer chitosan was used as a stabilizer and nontoxic chemical vitamin C was used as a reducing agent. Interestingly, the size of PdNPs could be controlled by adjusting the reaction temperature. The resulting PdNPs were characterized by TEM, XRD analysis, EDS analysis, UV-Vis, and DLS. When the temperature was increased from 25 to 95 °C, the shape of resulting PdNPs changed from flower shape to spherical shape and their hydrodynamic sizes decreased from 64 to 29 nm. The obtained PdNPs were relatively uniform in size and shape, and stable in aqueous solution. The photothermal behavior of PdNPs which resulted from the experiment at 95 °C was further tested. The photothermal results revealed that these PdNPs had excellent photostability and high photothermal conversion efficiency. In conclusion, the proposed method can be used for the preparation of PdNPs with desired sizes for various applications.