Electrochemical Reduction of Hexavalent Chromium on Two-step Electrosynthesized One-dimensional Polyaniline Nanowire

摘要

In this work, polyaniline (PANI) film was synthesized by the two-step electrochemical polymerizationmethod from sulfonic acid solution on the spectrographic pure graphite (SPG) surface. Scanningelectron microscope (SEM) characterization shows that the resulting PANI film had porousmorphology and loosely textured structure, which is composed of uniform 1D nanowires with anaverage diameter of about 100-200 nm. The electroreduction of Cr(VI) to the much less toxic trivalentstate (Cr(III)) was then studied on the PANI/SPG electrode. The effects of various parameters such ascathode potential, solution pH, PANI film thickness and electrolyte temperature on the Cr(VI) removalrate were investigated in detail. It was found that the negative cathod potential, low solution pH andappropriate PANI film thickness are benefit for the removal of Cr(VI). While the electrolytetemperature had no evident effect on the Cr(VI) electroreduction reaction. The electrochemicalstability of the PANI film after use in Cr(VI) reduction process was also investigated using cyclicvoltammetry and Fourier transfer infrared spectroscopy technologies.