Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2014-05-15

Journal: JOURNAL OF PHYSICAL CHEMISTRY C

Included Journals: Scopus、EI、SCIE

Volume: 118

Issue: 19

Page Number: 10509-10518

ISSN: 1932-7447

Abstract: 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.