One-Pot Synthesis of Monodispersed Silver Nanodecahedra with Optimal SERS Activities Using Seedless Photo-Assisted Citrate Reduction Method

This article presents a mechanistic study of silver nanodecahedra prepared by the method of photoassisted sodium citrate reduction under irradiation of blue light-emitting diodes (LEDs). This synthesis of silver nanodecahedra can be easily reproduced in the absence of silver seeds and can be completed in one-pot. The data suggest a combination of two processes including gradual growth from multiple-twinned particles and subsequent plasmon-mediated crystal growth. More than 85% of as-prepared silver nanoparticles are decahedra with edge lengths of 43.5 ± 5.2 nm. In addition, the as-prepared silver colloids exhibit a spectroscopic enhancement in comparison with spherical silver nanoparticle colloids and silver nanoprism colloids in the measurement of surface enhanced Raman spectroscopy (SERS) spectra of Rhodamin 6G, and with the decahedral silver colloids synthesized in the presence of PVP for detecting SERS signal of Rhodamin 6G. Overall, this photoassisted citrate reduction process is simple, and highly reproducible. As-prepared silver nanodecahedra are more stable and provide optimal SERS signal than those synthesized using commonly used plasmon-mediated photochemical methods.