Temperature coefficient of the potential of zero charge and entropies of formation for the interface of stepped faces of gold in contact with aqueous perchloric acid solutions

Abstract

The behaviour of several high Miller index crystal surfaces of gold is examined by cyclic voltammetry in 0.01 mol dm–3 perchloric acid solutions. The potentials of zero charge, Eσ= 0, and their temperature coefficients, dEσ= 0/dT for the stepped faces (332), (771), (320) and (410) are determined from a single minimum of the differential capacity curves. The results are compared with those existing for other stepped and low-index crystal faces in order to establish the relevance of the crystallographic structure in the double layer parameters. The influence of the step density and step orientation is discussed. The entropies of formation, S*, are calculated and discussed in terms of the gold–water interactions.