Abstract The electrochemical reduction of pertechnetate ions (TcO4−) have been studied in strongly alkaline media (0.3 ÷ 10 M aqueous NaOH) using electrochemical (cyclic voltammetry (CV); chronoamperometry (CA), chronopotentiometry (CP)) and spectroelectrochemical (UV-Vis OTTLE and Au-SERS) techniques. Such obtained results show formation of two types of Tc(V) species as intermediates in the electrochemical reduction of the pertechnetates. The soluble Tc(V) forms, detected by means of UV-Vis measurements are relatively stable but disproportionate to Tc(IV) and Tc(VII). The other type of Tc(V) containing products is present at the electrode surface. The latter species were detected and characterized by a band at 700 cm−1. The final products of the multistep reduction of the pertechnetates in NaOHaq are Tc(IV) compounds which composition depends on the electrolyte concentration. Thus, insoluble and adsorbed in the electrode surface TcO2 is the main product in 0.3 M NaOH while soluble polymeric Tc(IV) are the prevailing species observed in 10 M NaOH.

中文翻译：

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碱性溶液中锝的中间氧化态

摘要 使用电化学（循环伏安法 (CV)；计时电流法 (CA)、计时电位法 (CP)）和光谱电化学 (UV- Vis OTTLE 和 Au-SERS) 技术。这样获得的结果表明，在高锝酸盐电化学还原过程中，形成了两种类型的 Tc(V) 物种作为中间体。通过 UV-Vis 测量检测的可溶性 Tc(V) 形式相对稳定，但与 Tc(IV) 和 Tc(VII) 不成比例。另一种含 Tc(V) 的产物存在于电极表面。后一种物种被检测到并通过 700 cm-1 处的条带表征。NaOHaq 中高锝酸盐多步还原的最终产物是 Tc(IV) 化合物，其组成取决于电解质浓度。因此，不溶性和吸附在电极表面的 TcO2 是 0.3 M NaOH 中的主要产物，而可溶性聚合物 Tc(IV) 是在 10 M NaOH 中观察到的主要物质。