Mechanistic Study of Continuous Reactive Aromatic Organothiol Adsorption onto Silver Nanoparticles

    Authors

    S. M. Ansar; G. S. Perera; P. Gomez; G. Salomon; E. S. Vasquez; I. W. Chu; S. L. Zou; C. U. Pittman; K. B. Walters;D. M. Zhang

    Comments

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    Abbreviated Journal Title

    J. Phys. Chem. C

    Keywords

    SELF-ASSEMBLED MONOLAYERS; SURFACE-ENHANCED RAMAN; CHEMICAL ENHANCEMENT; VIBRATIONAL SPECTRA; LAYERED STRUCTURE; SCATTERING; AG; PARTICLE; GROWTH; THIOL; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, ; Multidisciplinary

    Abstract

    Organothiol (R-SH) (OT) adsorption onto silver nanoparticles (AgNPs) in water was studied for a series of aromatic OTs including p-methylbenzenethiol (p-MBT), p-benzenedithiol (p-BDT), and 2-mercaptobenzimidazole (2-MBI). Unlike the common view that OT forms monolayer adsorption on AgNPs, we found that these aromatic OTs continuously reacted with AgNPs through formation of RS-Ag complexes until complete OT or AgNP consumption occurred. The RS-Ag complex can remain on the AgNP surface, converting the AgNPs into core-shell structures. The OT adsorption onto AgNPs occurs predominately through reaction with silver oxide present on the AgNP surfaces before the OT addition or formed from environmental oxygen in the presence of OT. The RS-H protons are completely released when both p-MBT and 2-MBI reacted with AgNP, Ag2O, and AgNO3. However, a substantial fraction of S-H bonds remained intact when p-BDT, the only dithiol used in this work, is adsorbed on AgNPs or reacted independently with Ag2O and AgNO3. The new insights from this work should be important for understanding OT interaction with AgNPs in water and the SERS spectra of the OT adsorbed onto AgNPs.

    Journal Title

    Journal of Physical Chemistry C

    Volume

    117

    Issue/Number

    51

    Publication Date

    1-1-2013

    Document Type

    Article

    Language

    English

    First Page

    27146

    Last Page

    27154

    WOS Identifier

    WOS:000329331300035

    ISSN

    1932-7447

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