Anion-Doped TiO₂ Nanocatalysts for Water Purification under Visible Light

Abstract

Innovative sol–gel synthesis based on the self-assembling template method has been applied to synthesize mesoporous anion-doped TiO2 with N–F, S and C atoms using suitable surfactants and reagents, to improve simultaneously the structural, morphological, and electronic properties of TiO2 nanomaterials and achieve anion doping of titania with high visible light photoinduced reactivity. The incorporation of anion species in the titania structure resulted in the effective extension of TiO2 optical absorption in the visible range through the formation of intragap energy states. The anion-doped titania materials immobilized in the form of nanostructured thin films on glass substrates exhibited high photocatalytic efficiency for the degradation of the microcystin-LR (MC-LR) cyanotoxin, a hazardous water pollutant of emerging concern, under visible light irradiation. The development of these visible light-activated nanocatalysts has the potential of providing environmentally benign routes for water treatment.