Adsorption and self-sensitized, visible-light photodegradation of rhodamine 6G and crystal violet by one-dimensional lepidocrocite titanium oxide

A one-dimensional (1D) lepidocrocite structured titanium oxide photocatalyst, in which the cross-sections of the base unit are ≈5 × 7 Å2, was evaluated for its ability to decolorize and degrade two common dye pollutants, rhodamine 6G (Rh6G) and crystal violet (CV), under a full simulated solar spectrum as well as UV and visible light spectra seperately. The materials were characterized by X-ray diffraction as well as scanning and transmission electron microscopy. The dye decolorization was monitored via UV-visible spectroscopy. Mineralization was quantified by chemical oxygen demand. As a colloidal nanomaterial, the 1D material presents exceptional maximum uptake for Rh6G and CV at 1,850 mmol kg−1 and 1,930 mmol kg−1, respectively. They also become dye sensitized and can decolorize Rh6G and CV using visible light only, by an average of 90% and 64%, respectively, in 30 min when the starting catalyst-to-dye mass ratio is 1:1.