Pino Eduardo, Calderón Cristian, Herrera Francisco, Cifuentes Gerardo, Arteaga Gisselle
Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.
Departamento de Ingeniería Metalúrgica, Universidad de Santiago de Chile, Santiago, Chile.
Front Chem. 2020 May 5;8:365. doi: 10.3389/fchem.2020.00365. eCollection 2020.
As a model for the removal of complex organic contaminants from industrial water effluents, the heterogeneous photocatalytic degradation of Rhodamin 6G was studied using TiO-derived catalysts, incorporated in water as suspension as well as supported in raschig rings. UV and Visible light were tested for the photo-degradation process. TiO catalysts were synthesized following acid synthesis methodology and compared against commercial TiO catalyst samples (Degussa P25 and Anatase). The bandgap (E) of the TiO catalysts was determined, were values of 2.97 and 2.98 eV were obtained for the material obtained using acid and basic conditions, respectively, and 3.02 eV for Degussa P25 and 3.18 eV for anatase commercial TiO samples. Raschig rings-supported TiO catalysts display a good photocatalytic performance when compared to equivalent amounts of TiO in aqueous suspension, even though a large surface area of TiO material is lost upon support. This is particularly evident by taking into account that the characteristics (XRD, RD, Eg) and observed photodegradative performance of the synthesized catalysts are in good agreement with the commercial TiO samples, and that the RH6G photodegradation differences observed with the light sources considered are minimal in the presence of TiO catalysts. The presence of additives induce changes in the kinetics and efficiency of the TiO-catalyzed photodegradation of Rh6G, particularly when white light is used in the process, pointing toward a complex phenomenon, however the stability of the supported photocatalytic systems is acceptable in the presence of the studied additives. In line with this, the magnitude of the chemical oxygen demand, indicates that, besides the different complex photophysical processes taking place, the endproducts of the considered photocatalytic systems appears to be similar.
作为从工业废水中去除复杂有机污染物的模型，使用TiO衍生催化剂研究了罗丹明6G的多相光催化降解，该催化剂以悬浮液形式加入水中以及负载在拉西环中。对紫外光和可见光进行了光降解过程测试。TiO催化剂采用酸合成方法制备，并与商业TiO催化剂样品（德固赛P25和锐钛矿型）进行比较。测定了TiO催化剂的带隙（E），使用酸性和碱性条件获得的材料的带隙值分别为2.97和2.98 eV，德固赛P25为3.02 eV，锐钛矿型商业TiO样品为3.18 eV。与等量的水悬浮液中的TiO相比，拉西环负载的TiO催化剂表现出良好的光催化性能，尽管TiO材料的大表面积损失了。考虑到合成催化剂的特性（XRD、RD、Eg）和观察到的光降解性能与商业TiO样品良好吻合，以及在所考虑的光源存在下，TiO催化剂存在时观察到的RH6G光降解差异最小，这一点尤为明显。添加剂的存在会引起TiO催化的Rh6G光降解动力学和效率的变化，特别是在该过程中使用白光时，这表明存在复杂现象，然而在所研究的添加剂存在下，负载型光催化体系的稳定性是可以接受的。与此一致，化学需氧量的大小表明，除了发生不同的复杂光物理过程外，所考虑的光催化体系的最终产物似乎相似。
