In Situ Optical Second Harmonic Rotational Anisotropy Measurements of an Au(111) Electrode during Electrochemical Deposition of Tellurium

Abstract

The electrodeposition of Te on a single-crystalline Au(111) electrode was studied with 1064-nm-excited SH rotational anisotropy measurements. The SH rotational anisotropy was significantly changed with the first underpotential deposition (upd) of Te, and the bulk Te deposition attenuated the anisotropic character of the overall surface symmetry. The change in the SH rotational anisotropy during the first upd of Te was examined using two different models. The first model considered only the contribution of the Au(111) surface to the SHG response, while the second one took into account the contributions of both the Au(111) substrate and the adsorbed Te layer. In the former case, the change in the SH rotational anisotropy can be explained by considering the quenching of the nonlinear susceptibility of the Au(111) surface. The analysis based on the latter model resulted in a rotation angle of 608 for the adsorbed Te layer against the the Au(111) lattice. This value was not consistent with that expected from the adsorbate structure of the first upd layer of Te, i.e., ( 3× 3)R30°. Thus, the former model seems to be more appropriate to explain the present results. The SH rotational anisotropy measurement also suggests that the morphology became more isotropic after the bulk Te deposition.

Synthesis and characterization of Sb2Te3 nanofilms via electrochemical co-deposition method

“…That the bulk Te deposition does not occur until À50 mV in the acidic solution (pH: 1.5) suggests that surface limited atomic layers of Te might be formed at potentials in the range of 350 (C1) to À50 mV (bulk inset). These observations are very similar to those obtained in acidic solution by us [26] and others [27,28]. Fig.…”

One-step electrochemical preparation of the ternary (BixSb1−x)2Te3 thin films on Au(111): Composition-dependent growth and characterization studies

“…The electrochemical bulk deposition of Te does not occur until the potential reaches −50 mV in the acidic solution (pH 1.5). These observations agree with those obtained in acidic solution by us [27] and others [28,29]. Fig.…”

An SFG and DFG investigation of polycrystalline Au, Au–Cu and Au–Ag–Cu electrodes in contact with aqueous solutions containing KCN

“…A spectroelectrochemical approach has been recently taken: bulk field VIS-ERS, VIS-SHG and multiline SERS offer the possibility of significant breakthroughs in the study of electronic effects relevant to in situ Au-alloy work. In situ electrochemical SHG has been employed in the case of bimetallic interfaces, in the following UPD and electrodeposition studies: (i) polycrystalline Au electrodes and deposition of Ag [11], Pd [12] and Te [13]; (ii) Au(1 1 1) electrodes and deposition of Cu [14,15], Ag, Pb, Tl [15] and Te [16]; (iii) deposition of Cu on polycrystalline Ag [14]; (iv) deposition of Cd on polycrystalline Cu [17]; (v) polycrystalline Mo substrates and deposition of Cd [18] and In [19]. Regarding alloys, in situ SHG has been employed in the study of the corrosion of brass [20,21].…”