Abstract:
Electrochemical (EC) Scanning Tunneling Microscopy and Cyclic Voltammetry was
used to study the adsorption/self-assembly of Benzoic Acid (BZA) in either 0.05 M H2SO4 or 0.1
M HClO4 electrolyte solutions on a Au(111) substrate. BZA, unlike similar compounds, presents
a challenge to form long-range ordered nanostructures, because it only has one functional group
that allows for hydrogen-bonding. Therefore, the intermolecular interactions are relatively weak
and molecule-substrate interaction become more critical. Observations of long-range
nanostructures of BZA at these electrode/electrolyte interfaces was difficult in 0.05 M H2SO4
from competing adsorption of sulfate ions. 0.1 M HClO4 electrolyte was then used where
changing the concentration of BZA had a large role in the formation of adsorption phases.
Where, at/greater than 6 mM BZA revealed four different regions of adsorption phases, while at
less concentrations revealed disordered phases. EC potential also played a crucial role in this
study, and different nanostructure are revealed depending on the EC potentials applied.
