ANODIC-OXIDATION OF TELLURIDE IONS IN AQUEOUS BASE - A ROTATING-RING-DISK ELECTRODE STUDY

The anodic oxidation of telluride ions was studied in 1M NaOH using mainly hydrodynamic voltammetry. Thermodynamic (Pourbaix) analyses predicted stepwise oxidation of Te2- to [formula omitted], Te0, [formula omitted], and finally [formula omitted]. Consistent with this expectation, [formula omitted] was detected as a 1e− intermediate product at the ring, both in the forward Te2− → Te0, and in the reverse Te0 → Te2- electron transfer directions. Studies with authentic samples of [formula omitted] in 2M NaOH revealed that this species could be collected at the ring both in the oxidative (−0.80V vs. SCE) and in the reduction (− 1.20V) modes. Consequently, comparison of the ring response at −0.80V and −1.20V with the disk current profiles in 1 mM Te2−/1M NaOH provided further confirmation for the electrochemical generation of the [formula omitted] intermediate. Finally, further oxidation of Te0 to [formula omitted] and [formula omitted] was detected via cyclic and hydrodynamic voltammetry. © 1990, The Electrochemical Society, Inc. All rights reserved.