Adsorption of Anionic Thiols on Silver Nanoparticles

作者：Xu Bolei; Gonella Grazia^*; DeLacy Brendan G; Dai Hai Lung

来源：Journal of Physical Chemistry C, 2015, 119(10): 5454-5461.

DOI：10.1021/jp511997w

The adsorption of negatively charged 3-mercaptopropanesulfonate (MPS) on the surface of citrate stabilized Ag thartopartides in water is investigated using colloidal particle Surface sensitive techniques. The adsorption of this negatively charged thiol appears to be qualitatively different from that of neutral thiols and highlights the importance of repulsive interactions of electrostatic and aerie origins pertaining to charged thicilS. For the charged MPS thiol, the adsorption process occurs in two phases. At low Surface coverage, the intermolecular repialsiolleis negligible and the adsorption is dominated by the formation of the S-Ag bond, MPS molecules need to overcome an activation energy barrier (7.5 +/- 0.9) kcal/mol with an associated free energy change Delta G(ads) = -(14.3 +/- 0.3) kcal/mol and behave similar to neutrkthiols. On the other hand, at high surface coverage Where the repulsive interactions among MPS molecules cannot be neglected, the adsorption is Characterized by a higher E-a = (12.4 0.5) kcal/mol and lower Delta G(ads) = -(7.4 +/- 0.1) kcal/mol.

• 出版日期2015-3-12