可见光响应漂浮式微球光催化剂及其光降解模拟海水中苯酚

为了将光催化技术应用于有机物污染海水的治理,本文首先利用水热还原得到了具有可见光响应的还原商用P25光催化剂,而后将还原后的P25作为活性组分负载在透明的有机玻璃空心微球表面,制成漂浮式微球光催化剂.还原后的P25的表征结果表明,水热条件下金属还原作用会将P25中少量Ti~(4+)还原成Ti~(3+),同时催化剂表面还形成了无序化-内部结晶的核壳结构.这两种结构变化都会显著拓展还原P25催化剂的可见光响应.含苯酚模拟污染海水的光降解实验发现,降解低浓度苯酚时,漂浮型微球光催化剂显示了优异的降解效率,降解5 h的去除率达到了95%以上.由于还原P25光催化剂的稳定性并且漂浮式微球光催化剂能简易回收,在多次重复实验中微球光催化剂都可以保持较高的催化活性.

Preparation of visible light responsive floating microsphere photocatalysts for efficiently degrading phenol in simulated seawater

To employ the heterogenous photocatalysis for treating organic pollutants in seawater, metal reduction in hydrothermal process was first employed to obtain the reduced commercial TiO₂ photocatalysts (P25) with visible light responses. Then, these reduced P25 powders were loaded as active ingredients on the surface of hollow and transparent acrylic spheres to prepare floating microsphere photocatalysts. The characterization results for reduced P25 photocatalysts indicate that metal reduction in hydrothermal process could not only reduce a small amount of Ti⁴⁺ to Ti³⁺ in P25 photocatalysts, but also introduce the "disorder-crystalline" core-shell structures, which both significantly expanded the visible light response of the reduced P25 photocatalysts. From the degradation for phenol in seawater under irradiation of visible light, it was found that the performance of the floating microsphere photocatalysts was significantly high for degrading phenol with low concentration in seawater, and the removal rate exceeded 95% after photodegradation for 5 h. Due to the excellent stability of the reduced P25 photocatalysts and the simple recyclability of the floating spheres, the floating microsphere photocatalysts could maintain excellent catalytic activity in repeated photodegradation experiments.