Electrocatalytic Reduction Of Environmental Pollutants O-chloro Phenol Dechlorination

o-chlorophenol is environmental pollutant,which also is called 2-chlorophenol. 2-chlorophenol has been used on a large scale in chemical,petrochemical and electronic industries.Those compounds are widespread environmental contaminants.They are of great health and environmental concern because of their acute toxicity and strong bioaccumulation potential.2-chlorophenol is toxic and thermally stable.Once released into environment,they will accumulate in the surroundings and endanger human as well as its ecological environment over a long period of time.The USEPA had published 129 priority pollutants of 65 species,including 11 kinds of hydroxybenzene,including 2-chlorophenol.Therefore,the dechlorination of 2-chlorophenol has attracted extra attention,and becomes an important research subject of electrochemistry.The composition and preparation method of electrodes are the main influence factors on the structures of electro-catalytic electrode,which is important to electro-catalytic characteristics and Stability of electrodes.This paper focused on the preparation of palladium -modified titanium electrodes and palladium-pvp-modified titanium electrodes,and investigation on its characteristics.Taking 2-chlorophenol as model substrate,the factors that influence the electrochemical degradation of 2-chlorophenol was investigated.The relationship of electrode structure with the electrocatalysis characteristic,as well as the electrochemical dechlorination mechanism of 2-chlorophenol was preliminary researched.The preparation technology of palladium-modified titanium and palladium-pvp-modified titanium electrodes have been optimized in this paper.The preparation conditions,including the deposition potential,the deposition time and the loading amount of pvp were studied in detail. The impact of pvp on properties and stability of the palladium-modified titanium electrodes were studied,Experimental results showed that pvp doping of right amount was in favor of grain refining and could help to enhance the electrical conductivity and electro-catalytic ability of electrodes.The electrochemical characteristics of the palladium-modified titanium electrodes and palladium-pvp-modified titanium electrodes towards reduction of 2-chlorophenol in 1M NaOH solution and1M NaOH + 4mM HCOONa solution were investigated by cyclic voltammetry and AC impedance.It is disclosed that the dechlorination rate of 2-chlorophenol reached 63%after 140 minutes on palladium-pvp-modified titanium electrode in 1 M NaOH+4 mM HCOONa solution.The UV spectroscopic study showed that the electrolyzing reaction of 2-chlorophenol Produce phenol and HCl finally.The research on the electrochemical degradation mechanism of 2-chlorophenol indicated the reason why 2-chlorophenol can dechlorinate on palladium -modified titanium and on palladium-pvp-modified titanium electrodes.The reason was that the strong reducing property hydrogen that was from water electrolysis can continuous instead of the C1 of 2-chlorophenol that was adsorbed to the electrodes surface.