Preparation of foam-nickel composite electrode and its application to 2,4-dichlorophenol dechlorination in aqueous solution

Electrochemically reductive dechlorination of 2,4-dichlorophenol in aqueous solution was investigated on palladium/polymeric pyrrole film/foam-nickel (Pd/PPy/foam-Ni) electrode at ambient temperature. Pd/PPy/foam-Ni electrode, which provided catalytic surface for reductive dechlorination of 2,4-dichlorophenol, was prepared with an electrodepositing method. Cyclic voltammetry (CV) tests reveal that the hydrogen adsorption peak current on Pd/PPy/foam-Ni electrode was −150.4 mA. Scanning electron microscope (SEM) images show that PPy film modified the electrode surface characteristics. The dechlorination experimental results indicate that 2,4-dichlorophenol removal efficiency of 99.4% and current efficiency of 33.6% on Pd/PPy/foam-Ni electrode could be obtained under the conditions of dechlorination current of 5 mA and dechlorination time of 70 min in aqueous solution. The analysis of HPLC identifies that the final products were mainly phenol.