Preparation of series of Ti-based electrode and electro-catalytic oxidation of dye wastewater

Series of Ti-based electrodes of Ti/PbO2, Ti/SnO2-Sb2O3/PbO2, Ti/SnO2-Sb2O3/PbO2-Cu, Ti/SnO2-Sb2O3/PbO2-Ni and Ti/SnO2-Sb2O3/PbO2-Fe were prepared by thermal decomposition method. And with these electrodes as anodes and the acid fuchsin as simulated dye wastewater, the electro-catalytic oxidations of the simulated dye wastewater were performed. With the comparison of effects and reaction rate of different electrodes and the analysis of acid fuchsin oxidation process, it is shown that the electro-catalytic abilities of the Fe-modified electrode Ti/SnO2-Sb2O3/PbO2-Fe and Ni-modified electrode Ti/SnO2-Sb2O3/PbO2-Ni have higher removal efficiency and removal ratio while the Cu modified electrode Ti/SnO2-Sb2O3/PbO2-Cu did not present a obvious modified effect compared with those by Ti/PbO2 and Ti/SnO2-Sb2O3/PbO2. Based on the test data, first order kinetic models of these five electrodes were established. From the UV-VIS spectra of the Ti/SnO2-Sb2O3/PbO2-Fe electrode generated under the condition of 100 mg/L of initial concentration of acid fuchsin, 75 mA/cm2 of the density and 12 g/L of the electrolyte concentration (Na2SO4), it is found that the characteristic absorption peak of acid fuchsin at λmax=545 nm nearly disappeared in 60 min and the acid fuchsin was removed. However, some small molecular intermediate products were generated in the electro-catalytic oxidation.