Fabrication of nanofibrous PbO2 electrode embedded with Pt for decomposition of organic chelating agents

Abstract

A new fabrication method of nanofibrous metal oxide electrode comprising Pt nanofiber (Pt-NF) covered with PbO₂ on a Ti substrate was proposed. Pt-NF was obtained by performing sputtering deposition of Pt on the surface of electrospun poly(vinyl alcohol) (PVA) nanofiber on a Ti substrate, in which PVA was then removed by calcination (Ti/Pt-NF). Subsequently, by introducing PbO₂ to the Ti/Pt-NF using the electrodeposition method, a nanofibrous Ti/Pt-NF/PbO₂ electrode was finally obtained. Because the Ti substrate was covered by nanofibrous Pt, it had no environmental exposure and thus, was not oxidized during calcination. The crystal structure of the PbO₂ mainly consisted of β-form rather than α-form; the β-form was suitable for electrochemical decomposition and remained stable even after 20 h of use. The nanofibrous Ti/Pt-NF/PbO₂ electrodes showed 10% lower anode potential, 1.6 times higher current density at water decomposition potential, lower electrical resistance in the ion charge transfer resistance, and 2.27 times higher electrochemically active surface area than those of a planar-type Ti/Pt/PbO₂ electrode, and demonstrated excellent electrochemical performance. As a result, compared with the planar electrode, the Ti/Pt-NF/PbO₂ electrode showed more effective electrochemical decomposition toward nitrilotriacetic acid (80%) and ethylenediaminetetraacetic acid (83%), which are commonly used as chelating agents in nuclear decontamination.

Keywords: Chelating agents; Electrochemical decomposition; Nanofibrous PbO(2) electrode; Pt nanofiber.