Fabrication Of Graphene Electrodes And Their Electrocatalytic Reductive Debromination Of Polybrominated Diphenyl Ethers

Recently, with the production rising, hard-degradable and long-distance transfer, polybrominated diphenyl ethers (PBDEs) have been found everywhere on the earth. Studies show that PBDEs generally involved in potential carcinogenesis, harm to human's endocrine system, nervous and immune system. Due to its chemical stability, PBDEs can't be degraded easily. Electrochemical degradation attracts people's attention with its simple operation, high efficiency and non-secondary pollution. The material of electrode is a key factor of electrochemical degradation and can obviously affect the degradation efficiency. In considering the negative situation of PBDEs, platinum-loaded graphene electrode (Ti/Gr/Pd) and graphene electrode are fabricated in this work. And their degradation of PBDEs were investigated and displayed.The Ti/Gr/Pd electrode was synthesized by pyrolysis-electrophoresis-electroplate method. Graphene (Gr) was prepared by pyrolysis from graphite oxide which is made from Hummers method. And then, deposited the Gr and Pd nanoparticles by electrophoresis and electroplate separately. The composition and appearance of Ti/Gr/Pd were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopic (XPS), infrared spectrum (IR), and Raman spectrum. The optimal conditions of pyrolysis were 1000℃of reaction temperature,30 min of soaking time, and argon as shielding gas during the whole process. The optimal condition of electrophoresis were 0.1 g/L of Gr,0.1 g/L of Mg(NO3)2·6H2O,8 min of deposition time,850℃of annealing temperature, 30 min of annealing time. The optimal condition of electroplate were 0.001 M of PdCl2,1.25 mA/cm2 of current density and 5 min of deposited time.The Ti/Gr electrode was synthesized by hydrazine reduction and facile drying method. The Gr was reduced from graphite oxide and prepared Ti/Gr electrode by drying in the thermoelectric drying oven. The composition and appearance of Ti/Gr were characterized by TEM, atomic force microscope (AFM), XPS, IR, and Raman spectrum. The optimal conditions of preparing Ti/Gr electrode were 100 mL 0.4 g/L of GO dispersion solution,700μl of ammonia 40μl of hydrazine (80%),6 h of ultrasonic reaction time,50℃of drying temperature and 12 h of drying time.The debromination of BDE47 was carried out with Ti/Gr/Pd electrode synthesized by pyrolysis-electrophoresis-electroplate method and Ti/Gr electrode synthesized by hydrazine reduction and facile drying method respectively. The degradation efficiency of Ti/Gr/Pd electrode is about 90% in 3 h with -0.5 V voltage bias. And the degradation efficiency of Ti/Gr electrode is about 93% with-1.0 V voltage bias in 3 h. The tribromodiphenyl ether, bibromodiphenyl ether, monobromodiphenyl ether and ether were detected by gas chromatograph fitted with a mass spectrometer in the analysis of intermediate product.