Adsorptive removal and photocatalytic decomposition of cationic dyes on niobium oxide with deformed orthorhombic structure.

Nano-rod-shaped niobium oxide with a deformed orthorhombic structure (ortho-NbO) is first demonstrated as a selective adsorbent to remove cationic dyes wastewater. Ortho-NbO quickly adsorbs methylene blue (MB) with much greater capacity than reported inorganic adsorbents. Furthermore, ortho-NbO has a stronger affinity to cationic dye than anionic dye because cation exchange is involved in the adsorption process. The dye molecule adsorbed onto ortho-NbO can be degraded entirely under UV light irradiation because of its photocatalytic properties. Moreover, the regenerated ortho-NbO shows high reusability for use in additional adsorption processing. As described herein, new insights into the use of ortho-NbO as a photocatalytically regeneratable adsorbent for wastewater treatment are presented.