Effects of acid-modified crystalline titania (TiO2) on the photocatalytic degradation of the azo dye Remazol Red (RR) were investigated in order to design an effective catalyst for removing azo dye compounds from contaminated waste streams. The mechanism for RR photodegradation with acid-modified TiO2 (m-TiO2) was investigated using UV-visible spectroscopy and scanning electron microscopy (SEM). Modification of the TiO2 surface with hydrochloric acid (HCl) resulted in enhanced RR photodecomposition in water. The RR photodecomposition reactions are 19% more efficient than those with pure commercial TiO2 under UV radiation. The coupling between RR and TiO2 was improved by treating TiO2 with HCl. As a result, transfer of electrons from the conduction band of TiO2 to the RR was enhanced. The modification of crystalline TiO2 surface with HCl is a useful method for enhancing photodegradation of RR.
- positive surface