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论文类型：期刊论文

发表时间：2014-05-15

发表刊物：JOURNAL OF PHYSICAL CHEMISTRY C

收录刊物：SCIE、EI、Scopus

卷号：118

期号：19

页面范围：10509-10518

ISSN号：1932-7447

摘要：We recently reported that a wide range of ligands, including organothiols (OTs), can be completely desorbed from gold nanoparticles (AuNPs) by NaBH4 in water. In addition, NaBH4 induces desulfurization of 2-mercaptobenzimidazole (2-MBI) and 6-thioguanine (6-TG) on AuNPs. Reported herein is a systematic investigation of treating ligands adsorbed onto silver nanoparticles (AgNPs) with NaBH4. These results are compared and contrasted to those previously reported for the same set of ligands adsorbed onto AuNPs. Complete desorptions from AgNPs by NaBH4 in water were observed for nonspecifically adsorbed ligands that include Rhodamine 6G, adenine, thiophene, and halides (Cl-, Br-, and I-). These cleaned AgNPs can be reused for surface-enhanced Raman spectroscopy acquisition. However, OT figands could not be completely desorbed from AgNPs regardless of the amount of NaBH4 used in this work. NaBH4 can induce complete 6-TG desulfurization adsorbed on AgNPs, but the desulfurization rate is significantly slower than that on AuNPs. Transmission electron microscope analysis revealed that NaBH4 induced more extensive nanoparticle fusion for AgNPs than for AuNPs. A mechanistic study indicates that AgNPs serve as electron transfer hubs for hydrides in BH4- to protons in water. In addition to providing new insights for AgNP recycle, reuse, and catalytic applications, this work also highlights the significant differences in the structure and properties of OTs adsorbed on AuNPs and AgNPs.