High-performance electrocatalytic hydrodechlorination of pentachlorophenol by amorphous Ru-loaded polypyrrole/foam nickel electrode

Abstract

Ru/polypyrrole/foam Ni composite electrodes were electrochemically deposited for application to electrocatalytic hydrodechlorination of pentachlorophenol (PCP) in aqueous solution. We characterized the Ru/polypyrrole/foam Ni composite electrode by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and cyclic voltammetry. The polypyrroles were uniformly distributed on the nickel foam and Ru particles in the size range of 5–8 nm formed an amorphous layer on the polypyrrole/foam Ni composite surface. Compared with the crystalline electrodes of the Ru/foam Ni electrode, the Ru/polypyrrole/foam Ni composite electrodes showed better electrocatalytic dechlorination efficiency and greater stability. At a Ru loading of 0.06 mg/cm2, cathode potential of −1.2 V, and H2SO4 concentration of 0.2 mol/L, the degradation efficiency of PCP reached 94.3% with a dechlorination efficiency of 88%. This performance was well maintained after 8 cycles of reuse.