Electrodeposition of silver nanoparticles in the presence of different complexing agents by time‐resolved Raman spectroelectrochemistry

Abstract

Chemical and physical properties of metal nanoparticles (NPs) are determined not only by the synthesis method used to prepare them but also by the experimental conditions under the generation process takes place. One of the most important factors in the synthesis of NPs is the presence of complexing agents in the media that can change the size and shape of the NPs. The significant role of different complexing agents (cyanide, ethylenediaminetetraacetic acid, and ethylenediamine) in the electrochemical formation of silver nanoparticles (AgNPs) has been analyzed by time-resolved Raman spectroelectrochemistry. Electrochemical and spectroscopic responses, obtained simultaneously, provide suitable information about the changes that occur on the platinum electrode surface during the AgNPs electrodeposition. The morphology of AgNPs has been analyzed by ultraviolet–visible absorption spectroelectrochemistry, providing additional information and a detailed view of the electrodeposition process. The influence of the complexing agent used to generate AgNPs has been studied analyzing the surface-enhanced Raman scattering (SERS) effect of the modified substrate. Raman spectra show different SERS behavior depending on the complexing agent and therefore on the AgNPs generated. The relationship between SERS signals and the morphology of AgNPs has been displayed by scanning electron microscopy images. Time-resolved Raman spectroelectrochemistry confirms that chemical mechanism is necessary for SERS effect.