Enhancement of water soluble PDI-NapSO3H on the photocatalytic performance of Fe-TiO2 under visible light

In this paper, we successfully constructed two composite photocatalysts TiO 2 @PDI-NapSO 3 H and Fe-TiO 2 @PDI-NapSO 3 H by utilizing water-soluble PDI derivatives to bond with TiO 2 or iron-doped TiO 2 . Their photocatalytic performance to degrade phenol and diclofenac sodium (DCF) under visible light were investigated. The results show that PDI-NapSO 3 H can effectively improve the optical absorption properties of TiO 2 . Furthermore, the oxygen vacancy produced by doping of Fe in TiO 2 prevents the recombination of photogenerated carriers effectively. The larger conjugate plane of PDI-NapSO 3 H provides a convenient channel for the migration and separation of photogenerated carriers. Thus almost 99 % of phenol or DCF can be degraded by Fe-TiO 2 @PDI-NapSO 3 H within 90 or 120 min, respectively. However, the photocatalytic activity of Fe-TiO 2 @PDI-NapSO 3 H is better. The rate of phenol degradation is much higher than that of TiO 2 @PDI-NapSO 3 H. Further, through the photoelectric response characteristic analysis, radical trapping experiment and EPR test, the effects mechanism of the energy band structure, photogenerated carrier separation efficiency on the photocatalytic performance of Fe-TiO 2 @PDI-NapSO 3 H were discussed. In addition, the possible degradation pathways of DCF and the reasons for the obvious reduction of environmental toxicity after photocatalytic degradation were proposed.