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.

钯纳米颗粒（PdNPs）由于其出色的理化性质和广泛的应用而引起了人们的极大兴趣。纳米粒子的大小直接影响PdNP的性质和潜在应用。在这里，我们报道了一种可扩展，高效，绿色且一步一步的方法来合成尺寸可控的PdNP。这样，将生物相容性聚合物壳聚糖用作稳定剂，并将无毒的化学维生素C用作还原剂。有趣的是，可以通过调节反应温度来控制PdNP的大小。通过TEM，XRD分析，EDS分析，UV-Vis和DLS对所得的PdNP进行表征。当温度从25℃升高到95℃时，所得PdNP的形状从花形变为球形，并且其流体力学尺寸从64 nm减小到29 nm。所获得的PdNP在尺寸和形状上相对均匀，并且在水溶液中稳定。进一步测试了在95°C下实验产生的PdNPs的光热行为。光热结果表明，这些PdNP具有优异的光稳定性和高的光热转化效率。总之，所提出的方法可用于制备具有各种应用所需大小的PdNP。