Photocatalytic activity of K<inf>2</inf>Ti<inf>6</inf>O<inf>13</inf>/TiO<inf>2</inf> nanocomposite prepared using water extract of wood ash from waste for degradation of dye pollutants

Abstract

© 2020 K2Ti6O13/TiO2 nanocomposite photocatalysts were synthesized via a precipitation-calcination method using water extract of wood ash (WEWA) as a precipitating agent from waste. As the WEWA solution was basic and contained K+ ions, a chemical base and potassium source were not required for this synthesis. The as-synthesized products were calcined at 500, 600, 700, and 800 °C and the calcined products were characterized by X-ray diffractometry (XRD), transmission electron microscopy (TEM), UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS), X-ray photoelectron spectroscopy (XPS), and surface area analysis. The K2Ti6O13/TiO2 photocatalyst exhibited a high adsorption capacity for methylene blue (MB) and crystal violet (CV) molecules but a low adsorption capacity for rhodamine B (RhB). As the photocatalytic process for K2Ti6O13/TiO2 occurred through the dye sensitization mechanism, MB and CV were degraded faster than RhB. In the case of MB and CV, a small amount of H2O2 added to the dye solution improved the rate of photocatalytic degradation and reusability. Moreover, the treated MB and CV solutions were non-cytotoxic toward L929 and Vero cells.