The Preparation Of A New Type Of Pd/PPy-rGO/foam-Ni Electrode And Its Electrochemical Reduction Of Triclosan

In recent years,pharmaceutical and personal care products(PPCPs)represented by triclosan had been widely used.They are difficult to be degraded with strong stability.They have great toxicity to aquatic organisms and plants,and have potential interference with human endocrine systems.The ecological environment and human health have been seriously jeopardized.How to effectively control the pollution of such organic substances is a major problem in the field of environmental protection.A large number of studies have proved that electrocatalytic hydrodechlorination of chlorinated organic compounds by electrocatalytic reduction technology can effectively remove chlorinated organic compounds.This method which is easy to control and with high activity and less by-products,can not only ensure the dechlorination efficiency,but also use non-toxic and harmless organic solvents.Therefore,it has a good application prospect in the field of water treatment.In this method,the role of the electrodes is crucial.The catalytic properties of the electrode,such as the morphology,particle size and dispersibility of the catalytic metal supported on the electrode,largely determine the catalytic activity of the electrode.The poor dispersibility of the catalytic metal on the electrode,easy agglomeration and large particle size are urgent problems to be solved by this technology.Catalyst carrier was combined by reduced graphene oxide(rGO)with a conductive polymer for electrode.It could not only prevent the accumulation of the reduced graphene oxide sheets,but also effectively improve the cycle life and dispersibility of the polymer,provide more active site s for the catalytic metal loading,and improve the efficiency of the electrode for the treatment of pollutants.In this paper,a novel Pd/PPy-rGO/foam-Ni composite electrode was prepared by electrochemical method.The effects of polymerization potential and pyrrole concentration on the dechlorination performance of the composite electrode were studied.The surface morphology,crystal structure,size of catalyst particle,reduction degree of graphene oxide and conductivity of the electrode were analyzed by scanning electronic microscopy,transmission electron microscope,X-ray photoelectron spectroscopy,X-ray diffraction,Raman spectroscopy and electrochemical impedance spectroscopy.The results showed that Pd particles could be uniformly dispersed on the composite electrode due to the presence of reduced graphene oxide,which increased the contact area between the electrode and the contaminant and improved the removal efficiency.When the polymerization potential was 0.7 V,pyrrole concentration was 0.1 mol·L-1,polymerization time and temperature were 20 min and 0?,respectively,the removal efficiency could reach 100%at 180 min.The effects of dechlorination current,experimental temperature and initial concentration of pollutants during dechlorination system and the cycle stability of the electrode were investigated.The optimal conditions of dechlorination system was that the dechlorination current was 7 mA,the experimental temperature was 40?,and the initial concentration of pollutants was 50 mg·L-1.After the electrode was used for 5 times,the removal efficiency of triclosan could still reach 93.05%,and the Pd particles did not fall off.