Study On Application Of Gas Diffusion Electrode In The BEF And TiO₂/Ti Photoelectrocatalysis

In this paper, a gas diffusion electrode was made by hot pressure method and character by XRD. It was proved that the gas diffusion was able to absorb oxygen in the air that was reduced in situ into hydrogen peroxide via determination of hydrogen peroxide in the process.In an undivided compartment cell, a gas diffusion electrode was used as cathode generating hydrogen peroxide and Fe plate asan anode generating Fe2+ . During the Bipolar Electro-Fenton (BEF) system, organic contaminations in water were then efficiently oxidized with ,OH radicals produced from Fenton's reaction between H2O2 and Fe2+ generated in situ by the two electrodes.One of the most typical and difficultly degradated aromaticcompounds - phenol was the objective substance. The effects of some factors such as initial concentration of phenol, initial pH value of solution, operated current, temperature on the degradation rate of phenol were also investigated. The degraded depth of phenol was proved by UV-VIS technology. The mineralization degree of phenol in water by BEF was token through comparing the drop of TOC and CODcr with EF system using plate graphite. The possible intermediates in the degradation process were determined by FIPLC; moreover the reaction mechanism of degradation of phenol during the BEF course was deduced. The result of experiment indicated the gas diffusion electrode was able to absorb oxygen in the air, which was reduced into hydrogen peroxide in biggish pH value extension; The phenol in water was degraded efficiently by BEF process; furthermore the TOC and CODcr were dropped obviously; and it's degraded mechanism is like to Fenton method, primary intermediates were cis, tra-butene diacid.In this paper, Using the TiO2 /Ti photoelectrode as working electrode, the gas diffusion electrode as counter electrode, thesaturated calomel electrode as a referance electrode, the three photoelectrocalalytic system was built. The photoelectrocatalytic degradation of phenol was studied through selecting phenol as aimed material. The effects of some factors such as bias, initial concentration and pH value of solution, light intensity were also investigated. The intermediates in the degradation were determined by HPLC. The mineralization degree of phenol in water was token by the drop of TOC and CODcr of solution. The experimental results indicated that the gas diffusion of electrode in TiCVTi photoelectrocatalytic system was better for declining the CODcr of solution than the Cu plate as the counter electrode.