Poly(3,4-ethylenedioxythiophene)–Poly(styrenesulfonate)-Coated Glassy-Carbon Electrode for Simultaneous Voltammetric Determination of Uranium and Plutonium in Fast-Breeder-Test-Reactor Fuel

Abstract

Uranium (U) and plutonium (Pu) contents in nuclear materials must be maintained to a definite level in order to get the desired performance of the fuel inside the reactor. Therefore, high accuracy and precision is an essential criterion for the determination of U and Pu. We already reported the voltammetric determination of Pu in the presence of U in fast-breeder-test-reactor (FBTR) fuel samples, but interfacial, coupled chemical reactions between U(IV) and Pu(IV) enhance the peak-current density of U(VI) reduction and thus make voltammetry unsuitable for the quantitative determination of U in the presence of Pu. Thus, developing a voltammetric method for the simultaneous determination of U and Pu is highly challenging. Herein, we report the simultaneous voltammetric determination of U and Pu in 1 M sulfuric acid (HSO) on a poly(3,4-ethylenedioxythiophene) (PEDOT)-poly(styrenesulfonate) (PSS)-modified glassy-carbon (GC) electrode (PEDOT-PSS/GC). The modified electrode shows enhanced performance compared with bare GC electrodes. The peak-current density for U(VI) reduction is enhanced in the presence of Pu(IV), but it attains saturation when [Pu]/[U] in solution is maintained ≥2. Hence, under these circumstances, the variation of Pu concentration no longer influences the U(VI)-reduction peak, and thus the quantitative determination of U in the presence of Pu is possible. No interference is observed from commonly encountered impurities present in FBTR fuel samples. This method shows accuracy and precision comparable to those of the biamperometry method. High robustness, fast analysis, simultaneous determination, reduced radiation exposure to the analyst, and ease of recovery of U and Pu from analytical waste makes it a suitable candidate to substitute the presently applied biamperometry method.

High effectiveness of pure polydopamine in extraction of uranium and plutonium from groundwater and seawater

“…The observed positions and quantity of the redox couples differ from the previously reported ones for U or Pu in literature for bare GC electrode and various conditions. [53][54][55] In particular, uranyl(VI) nitrate in conditions close to those of this study showed only one redox couple of U(VI)/U(V) in cathodic region at À0.01(ox) V/ À0.25(red) V (vs. Ag/AgCl). 53 A quite similar behavior with one redox couple of U(VI)/U(V) at À0.075/À0.2 V (vs. Ag/AgCl) was found for uranyl(VI) perchlorate on Pt electrode in aqueous solution of 0.1 M LiClO 4 .…”

“…graphene oxide (GO) or conducting polymer PEDOT-PSS) with or without pre-adsorbed radionuclide species. [53][54][55] In particular, in the case of GO layer with the pre-adsorbed uranyl deposited on GC electrode the position of U(VI)/U(V) redox couple shis to anodic region by around 205-250 mV in comparison to bare GC. 53 Moreover, the shape of the peaks became more complicated and additional weakly pronounced redox couple at 0.21 V/0.13 V appeared that suggested both change of valence state of U and altering the electronic conguration of uranyl(VI) cations due to their coordination with functional groups on the GO surface.…”

“…53 While to our knowledge there is no published information on electrochemistry of highest valence state of Pu on adsorbent coated electrodes, it is found that the GO or PEDOT:PSS layers on GC showed enhanced electrocatalytic activity towards Pu(IV)/ Pu(III) redox couple and signicantly decreased the cathodic and anodic peak potentials in acidic media (1 M H 2 SO 4 ). 52,54,55 In particular, due to the GO inuence this redox couple shied from 0.666 V/0.092 V to 0.605 V/0.398 V (ref. 54) while due to the PEDOT:PSS inuence the couple shied from 0.674 V/0.132 V on the bare GC electrode to 0.540 V/0.496 V. 62 If compare the known electrochemical transitions of U and Pu bearing species in different valence states [53][54][55][56][57][58][59][60][61][62] on bare and coated electrodes with positions of the redox couples of the PDA-U and PDA-Pu samples (Fig.…”

“…52,54,55 In particular, due to the GO inuence this redox couple shied from 0.666 V/0.092 V to 0.605 V/0.398 V (ref. 54) while due to the PEDOT:PSS inuence the couple shied from 0.674 V/0.132 V on the bare GC electrode to 0.540 V/0.496 V. 62 If compare the known electrochemical transitions of U and Pu bearing species in different valence states [53][54][55][56][57][58][59][60][61][62] on bare and coated electrodes with positions of the redox couples of the PDA-U and PDA-Pu samples (Fig. 6) one can see that in the case of PDA the shis of these transitions along the potential axis and, therefore, specic interactions of PDA with the actinides species are signicantly stronger than in the cases of GO or PEDOT:PSS.…”

Template‐free Electrosynthesis of Platinum Nano‐Cauliflowers for Catalysing Electron Transfer Reaction of Plutonium

“…The heterogeneous electron transfer reaction of Pu(IV)/Pu (III) is found to be an electrochemically quasi-reversible redox reaction, which greatly depends on the nature of the electrode materials. Hence, the electrochemistry of Pu (IV)/Pu(III) had been investigated on glassy carbon electrode [19], platinum electrode [20], and electrodes modified with platinum nanoparticles [10], ruthenium nanoparticles [21], poly(3,4-ethylenedioxythiophene) polystyrene sulfonate [22,23], polyaniline and single-walled carbon nanotubes [24], graphene [25], and electrochemically reduced graphene oxide [26]. However, none of the modified electrodes practically could be able to replace the conventional Pt electrode for the routine electrochemical analysis of Pu.…”