Instituto de Ciencia de Materiales de Sevilla, Centro Mixto Universidad de Sevilla-CSIC, Sevilla, Spain.
Photochem Photobiol. 2013 Jul-Aug;89(4):832-40. doi: 10.1111/php.12054. Epub 2013 Mar 4.
Bi2 WO6 and Bi2 WO6-TiO2 (5% molar Ti) nano-heterostructures were synthesized by a hydrothermal method. The properties of the synthesized catalysts were characterized, having high photoactivity for Rhodamine B degradation under sun-like illumination, explained by a synergetic mechanism previously proposed through UV and visible induced processes, in which the photosensitization effect of Rhodamine B is considered. We now report that using Phenol, a molecule which does not lead the photosensitization process, the photoactivity decreased considerably, thus emphasizing how important is the model molecule selected as degradation substrate for evaluating the photoactivity. The photocatalytic properties of the synthesized catalysts have been evaluated by exposing a mixture of Rhodamine B and Phenol in water, to different illumination conditions. It can be confirmed that the photoinduced mechanism via the photosensitization of Rhodamine B is a key factor responsible for the increase on the photocatalytic activity showed by the Bi2 WO6-TiO2 compound and that the degradation mechanism of Rhodamine B is not changed by the simultaneous presence of other transparent substrate as Phenol.
通过水热法合成了 Bi2 WO6 和 Bi2 WO6-TiO2（5%摩尔 Ti）纳米异质结构。对合成催化剂的性质进行了表征，发现其在模拟阳光照射下对罗丹明 B 的降解具有很高的光活性，这可以通过之前提出的 UV 和可见诱导过程中的协同机制来解释，其中考虑了罗丹明 B 的光敏化作用。我们现在报告说，使用苯酚，一种不会导致光敏化过程的分子，光活性大大降低，因此强调了选择作为降解底物的模型分子对于评估光活性的重要性。通过将罗丹明 B 和苯酚在水中的混合物暴露在不同的光照条件下，评估了合成催化剂的光催化性能。可以确认，通过罗丹明 B 的光敏化的光诱导机制是导致 Bi2 WO6-TiO2 化合物光催化活性增加的关键因素，并且罗丹明 B 的降解机制不会因同时存在其他透明底物如苯酚而改变。
