Abstract Electrochemical reduction of pertechnetate ions is studied in acetate solutions on both mercury dropping and solid electrodes. It is found that electroreduction of TcO4− ions on the mercury dropping electrode occurs stepwise via the following route Tc(VII) → Tc(IV) → Tc(III) → Tc(0). Ammonium ions affect the reduction of pertechnetate ions by shifting potentials of polarographic waves in a positive direction. Diffusion coefficients of Tc(VII) species in acetate solutions decreased from ~1 · 10−5 cm2 s−1 in a solution containing 2 mol dm−3 acetate ions to ~1.2 · 10−6 cm2 s−1 in a solution containing 8 mol dm−3 acetate ions. The Stokes radius of pertechnetate ion is 0.19 ± 0.01 nm. Technetium coatings were characterized using X-ray absorption spectroscopy (XANES/EXAFS). It is shown that technetium is in the metallic state in the electrolytic deposits; however, the obtained metal is amorphous. The Tc-Tc interatomic distances and coordination numbers of Tc atoms in the deposits are determined. The distance between technetium atoms in the electrodeposits is slightly less (0.262 nm) compared to technetium foil (0.272 nm).

中文翻译：

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高锝酸盐离子在浓醋酸溶液中的电还原

摘要 研究了高锝酸盐离子在醋酸溶液中在滴汞电极和固体电极上的电化学还原。发现滴汞电极上TcO4-离子的电还原通过以下路线逐步发生：Tc(VII)→Tc(IV)→Tc(III)→Tc(0)。铵离子通过将极谱波的电位向正方向移动来影响高锝酸盐离子的还原。Tc(VII) 物质在乙酸盐溶液中的扩散系数从含有 2 mol dm-3 乙酸根离子的溶液中的~1 · 10−5 cm2 s−1 降低到含有 8 mol dm−3 乙酸根离子的溶液中~1.2 · 10−6 cm2 s−1 mol dm-3 醋酸根离子。高锝离子的斯托克斯半径为 0.19 ± 0.01 nm。锝涂层使用 X 射线吸收光谱 (XANES/EXAFS) 进行表征。结果表明，锝在电解沉积物中呈金属态；然而，获得的金属是无定形的。确定沉积物中 Tc 原子的 Tc-Tc 原子间距离和配位数。与锝箔 (0.272 nm) 相比，电沉积物中锝原子之间的距离略小 (0.262 nm)。