| Due to its wide distributing in environment, high toxicity and resistivity to degradation, polybrominated diphenyl ethers(PBDEs) have received more attention, and many methods have been investigated to degradate PBDEs, such as biologic method, photochemical method, reduction by zero-value iron and electrochemical method. Among these methods, the electrochemical reduction has caused world-wide interests due to its high efficicency, simple operation, and friendly to the environment. In this work, platinum-loaded graphene electrode (Pt/graphene/Ti) is fabricated and its ability of electrocatalytic reductive debromination (using PBDEs as target pollutant) is displayed.Graphene electrode was prepared by chemical vapor deposition (CVD) and electrophoresis, respectively. The microstructure and composition of the graphene electrode were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectrum. The effect of different preparing conditions on the microstructure and composition of the graphene electrode was investigated. We optimized preparing conditions for the two methods respectively by analyzing. The optimal conditions for CVD method were 10 mg/mL of dicyclopentadienyl iron,0.095% of thiophene,950℃of the reaction temperature and 20 min of deposition time. The optimal conditions for electrophoresis method were 0.2 mg/mL of graphene,0.2 mg/mL of Mg(NO3)2·6H2O,5 min of electrophoresis time and calcined at 850℃for 1 hour.Pd nanoparticles were loaded on the surface of graphene electrode by a constant current electrodeposition method to synthesize the Pd/graphene/Ti electrode. The effects of current density and deposition time on the morphology and property of the electrode were investigated. The TEM image indicated that Pd particles, whose average diameter was about 5 nm, were dispersed uniformly on the surface of graphene. The optimized preparation conductions were 1.25 mA/cm2 of current density and 5 min of deposited time. The energy-dispersive X-ray (EDX) proved that the Pd nanoparticles were dispersed on the graphene surface. The excellent electrochemical property of the Pd/graphene/Ti electrode was shown by the analysis of cyclic voltammetry.The electrocatalytic reductive debromination of the 2,2',4,4'-tetrabromo diphenyl ether (BDE47) was carried out by using the Pd/graphene/Ti electrode, which were prepared by chemical vapor deposition and electrophoresis, respectively. The effect of synthesized conditions of electrode and working voltage on the debrominated degradation efficiencies were investigated. With Pd/graphene/Ti electrode, in 3 hours, the degradation efficiency of BDE47 was up to 96%(the supporting electrolyte and working voltage were 0.05 mol/L H2SO4 and-0.8 V, respectively). The performance of the Pd/graphene/Ti electrode was better than the Pd-loaded Ti electrodes (Pd/Ti) and Pd-loaded CNTs electrode (Pd/CNTs/Ti). In the same condition, the performance of the Pd/graphene/Ti electrode, which was prepared by the electrophoresis method, was better than that prepared by the chemical vapor deposition method. The tribromodiphenyl ether dichlorobiphenyl, biphenyl ether and monobromodiphenyl eher were detected by the qualitative analysis of the debrominated production. This confirmed the process of electrocatalytic reductive debromination.In a word, the optimal conditions for the synthesis of Pd/graphene/Ti electrode and electrocatalytic reductive debromination of PBDEs were investigated and the debrominated productions were qualitative analyzed in this dissertation. Compared with other plate electrode, graphene electrode has better performance in the electrocatalysis. These results will provide the theoretical and experimental basis for the application of graphene in the field of electrocatalytic engineering.
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