Synthesis of Ag Nanocubes 18-32 nm in Edge Length: The Effects of Polyol on Reduction Kinetics, Size Control, and Reproducibility

• Type of Material: Article
• Authors: Yi Wang, Georgia Institute of Technology; Yiqun Zheng, Georgia Institute of Technology; Cheng Zhi Huang, Southwest University; Younan Xia, Emory University
• Language: English
• Date: 2013-02-06
• Publisher: American Chemical Society
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2013 American Chemical Society.
• Final Published Version (URL): http://dx.doi.org/10.1021/ja311503q
• Title of Journal or Parent Work: Journal of the American Chemical Society
• ISSN: 0002-7863
• Volume: 135
• Issue: 5
• Start Page: 1941
• End Page: 1951
• Grant/Funding Information: Y.X. was also partially supported by the World Class University (WCU) program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (R32-20031).; This work was supported in part by research grants from NIH (R01, CA 138527); and NSF (DMR, 1215034); and startup funds from Georgia Institute of Technology.; As a visiting Ph.D. student from Southwest University, Y.W. was also partially supported by a Fellowship from the China Scholarship Council (CSC).
• Keywords: SEED-MEDIATED SYNTHESIS; Science & Technology; Physical Sciences; PHASE-TRANSFER; GOLD NANOPARTICLES; NANOCRYSTALS; SILVER NANOSTRUCTURES; CATALYSIS; Chemistry; Chemistry, Multidisciplinary; SURFACE-PLASMON RESONANCE; FACILE SYNTHESIS; CHEMISTRY; SHAPE-CONTROLLED SYNTHESIS
• Research Categories: Chemistry, General; Engineering, Biomedical

Abstract

This article describes a robust method for the facile synthesis of small Ag nanocubes with edge lengths controlled in the range of 18-32 nm. The success of this new method relies on the substitution of ethylene glycol (EG) - the solvent most commonly used in a polyol synthesis - with diethylene glycol (DEG). Owing to the increase in hydrocarbon chain length, DEG possesses a higher viscosity and a lower reducing power relative to EG. As a result, we were able to achieve a nucleation burst in the early stage to generate a large number of seeds and a relatively slow growth rate thereafter; both factors were critical to the formation of Ag nanocubes with small sizes and in high purity (>95%). The edge length of the Ag nanocubes could be easily tailored in the range of 18-32 nm by quenching the reaction at different time points. For the first time, we were able to produce uniform sub-20 nm Ag nanocubes in a hydrophilic medium and on a scale of ∼20 mg per batch. It is also worth pointing out that the present protocol was remarkably robust, showing good reproducibility between different batches and even for DEGs obtained from different vendors. Our results suggest that the high sensitivity of synthesis outcomes to the trace amounts of impurities in a polyol, a major issue for reproducibility and scale up synthesis, did not exist in the present system.