Department of Chemistry, Tongji University, 1239 Siping Road, 200092 Shanghai, China.
Environ Sci Technol. 2010 Mar 1;44(5):1780-5. doi: 10.1021/es903201m.
A novel electrosorption-photocatalysis synergistic electrode of TiO(2)/carbon aerogel (TiO(2)/CA) is prepared. The thermal stability and dispersion of the anatase TiO(2) particles are well facilitated by the porous and discontinuous microstructure of CA. The degradation experiments show that the TiO(2)/CA material is not only a good photocatalyst but also an excellent electrosorptive electrode. The TiO(2)/CA is easily molded to an agglomerate electrode. The opaque wastewater with dyestuff is degraded effectively by the electrosorption-promoted photocatalytic process on this electrode. For the simulated methylene blue (MB) wastewater (150 mg L(-1)), the rate constant of MB degradation in the electro-assisted photocatalytic process with the conventional ITO-supported TiO(2) (TiO(2)/ITO) is 0.55 x 10(-3) min(-1) and that the electrosorption-promoted photocatalysis with TiO(2)/CA is 10.27 x 10(-3) min(-1), which is 18 times the former. In the electrosorption-promoted photocatalytic process with TiO(2)/CA, the energy consumption removing per unit TOC is only 15% of that in the electro-assisted photocatalysis with TiO(2)/ITO, because the electrosorption is a nonfaradic process irrelative to any electron transfer and requires very low consumption. This study provides a new method for exploring highly efficient electrosorption-promoted photocatalytics technology in the treatment of opaque wastewater.
一种新型的 TiO2/碳气凝胶（TiO2/CA）电吸附-光催化协同电极被制备。CA 的多孔和不连续的微观结构很好地促进了锐钛矿 TiO2 颗粒的热稳定性和分散性。降解实验表明，TiO2/CA 材料不仅是一种良好的光催化剂，也是一种优异的电吸附电极。TiO2/CA 很容易被模制成团聚电极。在这种电极上，不透明的染料废水通过电吸附促进的光催化过程得到有效降解。对于模拟的亚甲基蓝（MB）废水（150mg/L），在具有常规 ITO 负载 TiO2（TiO2/ITO）的电辅助光催化过程中，MB 降解的速率常数为 0.55x10-3min-1，而 TiO2/CA 的电吸附促进光催化的速率常数为 10.27x10-3min-1，是前者的 18 倍。在 TiO2/CA 的电吸附促进光催化过程中，去除单位 TOC 的能耗仅为 TiO2/ITO 的电辅助光催化的 15%，因为电吸附是非法拉第过程，与任何电子转移无关，所需能耗非常低。本研究为探索不透明废水处理中高效电吸附促进光催化技术提供了一种新方法。
