Surface Stress-Charge Response of a (111)-Textured Gold Electrode under Conditions of Weak Ion Adsorption

We report a cantilever bending investigation into the variation of surface stress, f, with surface charge density, q, for (111)-textured thin films of gold in aqueous NaF and HClO4. The graphs of f(q) are highly linear, and the surface stress-charge coefficients, df/dq, are −1.95 V for 7 mM NaF and −2.0 V for 10 mM HClO4 near the potential of zero charge. These values exceed some previously published experimental data by a factor of 2, but they agree with recent ab initio calculations of the surface stress-charge response of gold in vacuum.