Electrochemical behavior of graphite in LiCl and LiCl melts containing up to 1 wt% Li 2 O was studied by using cyclic voltammetry and electrolysis, in the context of its probable use as anode in the electrochemical reduction of solid UO 2 in the molten salt at 650 • C. The lithium deposition and chlorine evolution potentials of LiCl melt were determined by CV of tantalum (cathodic polarization) and graphite (anodic polarization) working electrodes as −2.19 V and +1.21 V vs Ni/NiO reference electrode respectively. In LiCl-Li 2 O melts, carbon dioxide was formed on the graphite WE from > +0.75 V onwards and its current and potential range of formation increased with increase in the Li 2 O content of the melt. Cathodic polarization of a UO 2 disc WE in LiCl-1 wt% Li 2 O melt showed that the reduction of UO 2 to U occurs at −2.18 V and the lithium metal deposition on it at −2.36 V. Electro-reduction experiments carried out with a dense UO 2 pellet cathode and graphite anode in both LiCl and LiCl-Li 2 O melts proved that the surface of the pellet was reduced to U metal at ≥ −2. Nuclear energy is considered as a major source of electricity for the present and future demands of the modern world. Sodium cooled fast reactor with metal fuel is proposed as one of the future reactor systems in the Generation IV concept and such reactors are considered to be inherently safe, economically viable and resistant to nuclear proliferation.1 U-Pu-Zr alloy is used as the metal fuel and hence production of these metals is of importance in the context of nuclear electricity. These metals have been produced from their oxides by the conventional chemical processes for the past several decades and there has been a great deal of interest to develop more efficient methods of production of the metals directly from the oxides.Spent metal fuels are reprocessed by pyrometallurgical process, in which the major and minor actinides are recovered by an electrorefining process carried out in a molten bath of LiCl-KCl at 500• C.
2Most of the nuclear reactors use uranium oxide and mixed oxide of uranium and plutonium (MOX) as the fuel and the spent fuel containing UO 2 and PuO 2 along with other oxides and fission products can be processed to obtain U and Pu for preparation of metal fuel. Reprocessing of spent oxide fuels by the molten salt electrorefining process is difficult as the oxides do not dissolve in the molten chlorides.Hence an intermediate process is required to convert the spent-oxide fuel to a metal form, which can be subsequently electrorefined to separate the actinides of interest. Chemical reduction of the spent oxide fuel by lithium metal in molten LiCl at 650• C was reported in this context. 3 The process required handling of large quantities of highly reactive lithium metal. The process also demanded frequent change of the molten bath due to build up of Li 2 O and hence the use of large quantities of the molten salt. Obviously these factors raise issues of safety of handling and storage of hygroscopic salt and highly irradiated fu...
A precise and sensitive electrochemical sensor based on a simple graphene oxide modified carbon paste electrode (GO/CPE) was successfully fabricated for simultaneous detection of epinephrine (EPN), uric acid (UA), and ascorbic acid (AA). The GO/CPE displays better electrochemical activity towards EPN by largely improving the current sensitivity and selectivity. Large peak separation allowed this sensor to analyze EPN individually and simultaneously in the mixture of AA and UA. The developed sensor showed good reproducibility, and stability. The sensor exhibited acceptable performance in wide concentration range (0.1–2000 μM) with a limit of detection down to 50 nM.
This paper demonstrates a highly sensitive, selective, biocompatible and cost-effective method for the simultaneous determination of Epinephrine (EPN), Uric acid (UA) and Tyrosine (TYR). Superior electrochemical performance was achieved using ZnO/RGO/CPE modified electrodes compared to individual components, graphene oxide (GO) and ZnO modified electrodes. The electrochemical activity of the fabricated sensor is examined through cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry (CA). A sharp increase in anodic peak current and negative shift in the electrode potential upon modification indicates enhanced electrocatalytic activity of ZnO/RGO/CPE. Well distinguishable voltammetric peaks with base-to-base separation and better anodic current were achieved with modified electrode in a mixture of EPN, UA and TYR. The developed sensor exhibits good electrocatalytic activity and an excellent rate of electron transfer arising from the synergistic effect of ZnO and RGO. The detection limit of each biomolecule calculated using DPV is 310 pM for EPN, 340 pM for UA and 730 pM for TYR. The practical feasibility of the proposed sensor is demonstrated by recording satisfactory voltammetric responses in human urine and serum samples.
TiO2/RGO nanocomposites were synthesised via a simple one-pot hydrothermal method and used as a modifier in carbon paste electrode for the sensitive determination of serotonin.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.