空气电极/AC作载体对TiO2光催化性能的影响

研究了空气电极和活性碳 (AC)作载体对TiO2 光催化氧化活性艳红 (K 2BP)性能的影响 .实验结果表明 ,用空气电极 /AC作载体能显著提高TiO2 的光催化反应速度 ;空气电极不仅具有良好的合成H2 O2 的性能 ,而且对TiO2 光催化剂可产生大约 +0 .5V的偏压作用 ,大大减小了TiO2 光生电荷的复合几率 ;AC对有机物分子良好的吸附作用提高了有机物分子在TiO2 表面及周围的富集浓度 ,其含量在 2 1%左右可使光催化剂达到最佳的催化效果 .复合电极工作电流密度对活性艳红的氧化脱色速度有影响 ,i=15mA/cm2 ,速度达到最大 ;活性艳红分子在复合电极表面的吸附受溶液pH值的影响 ;提出了复合电极的工作原理 .

The Effect of Air Electrode/AC Supported on Photocatalytic TiO2 for Photo Degradation

The photocatalytic degradation of activated red in the aqueous solution was studied using TiO 2 supported on air electrode and active carbon(AC) as photocatalysts. It was found that the photocatalytic reaction rate of TiO 2 was obviously increased by the presence of air electrode and AC supported. The air electrode which has functions of synthesizing H 2O 2 in situ and photo-catalysis was reported. The results also implied that biasing of the electrode at +0.5 V led to efficient charge separation. The current density of air (oxygen) electrode had effect on the oxidation rate of azo dye molecule, i=15 mA/cm2, and the rate could reach maximum. With AC mass fraction of about 21% the oxidation rate for TiO 2/AC was obviously larger than that for TiO 2, but the result was contrary to this for higher AC mass fraction (>30%). The experiment results showed that because TiO 2 was supported on active carbon, the effective surface area of the photocatalysts and their absorbability for organic molecules can be increased. The pH in solution had effect on the oxidation rate of organic molecules.