In this report, photochemical synthesis of monodispersed gold (Au) and silver (Ag) nanoparticles (NPs) was reported using cholic acid functionalized star poly(DL-lactide) (CA-(PDLLA)) as a capping and reducing agent. CA-(PDLLA) was synthesized by ring-opening polymerization (ROP) of DL-lactide with a feed ratio of 1:120 (cholic acid: DL-lactide). The molecular weight of CA-(PDLLA) was measured by using the gel permeation chromatography (GPC) technique. The thermal properties of the polymer and its nanocomposite materials were studied by thermogravimetric analysis (TGA). The optical properties of Ag and Au NPs were studied by UV–visible absorption spectroscopy. Morphological studies and size of the polymer-nanocomposites were assessed by using field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) techniques. The percentage composition of Au and Ag present in the polymer-nanocomposites was calculated using energy-dispersive X-ray spectroscopic (EDX) analysis. Finally, the synthesized polymer-metal nanocomposites were used as heterogeneous catalysts for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as a model reaction and the apparent rate constant (k_app) values of CA-(PDLLA)-AuNPs and CA-(PDLLA)-AgNPs were found to be 5.76 × 10⁻⁴ s⁻¹ and 19.7 × 10⁻⁴ s⁻¹, respectively.

在本报告中，报道了使用胆酸功能化星形聚（DL-丙交酯）（CA-（PDLLA））作为封端剂和还原剂来光化学合成单分散金（Au）和银（Ag）纳米颗粒（NP）。CA-(PDLLA)通过DL-丙交酯的开环聚合(ROP)合成，进料比为1:120(胆酸:DL-丙交酯)。CA-(PDLLA)的分子量通过使用凝胶渗透色谱(GPC)技术测量。通过热重分析（TGA）研究了聚合物及其纳米复合材料的热性能。通过紫外-可见吸收光谱研究了Ag和Au NPs的光学性质。使用场发射扫描电子显微镜（FE-SEM）和高分辨率透射电子显微镜（HR-TEM）技术对聚合物纳米复合材料的形态研究和尺寸进行了评估。使用能量色散 X 射线光谱 (EDX) 分析计算聚合物纳米复合材料中金和银的百分比组成。最后，合成的聚合物-金属纳米复合材料用作多相催化剂，将 4-硝基苯酚 (4-NP) 还原为 4-氨基苯酚 (4-AP) 作为模型反应，并得到了 CA 的表观速率常数 (k app )_值发现-(PDLLA)-AuNPs和CA-(PDLLA)-AgNPs分别为5.76×10^-4 s^-1和19.7×10^-4 s^-1。