Preparation of titania-containing photocatalysts from metallurgical slag waste and photodegradation of 2,4-dichlorophenol

A low cost, high performance titania-containing metallurgical slag photocatalysts (TCMSPx, x = H2SO4, HNO3, HCl) were prepared using a hydrothermal method. The prepared TCMSPx were characterized in terms of visual, physical and chemical properties. The photocatalytic activity of the TCMSPx was evaluated via the photodegradation of 2,4-dichlorophenol (2,4-D) in aqueous solution. The results showed that the characteristics and photocatalytic activity of TCMSPx were strongly affected by acidic solutions used during the acidolysis. TCMSP H 2 SO 4 exhibited better characteristics and higher photocatalytic activity than TCMSP HNO 3 and TCMSPHCl. OH radicals from TCMSP H 2 SO 4 were produced under UV, visible and solar light irradiation. The degree of photodegradation of 2,4-D by TCMSP H 2 SO 4 was 80.1%, 50.0% and 61.5% under UV, visible and solar light irradiation respectively. In addition, the removal of chlorine functional group on the 2,4-D benzene ring and the production of intermediates during 2,4-D photodegradation were monitored using ion chromatography, UV–vis spectra and high performance liquid chromatography of 2,4-D before and after photodegradation.