Photocatalytic properties of Cr–TiO₂ nanocomposite photoelectrodes produced by electrochemical anodisation of titanium

Abstract

Different Cr–TiO₂ nanocomposite photoelectrodes were fabricated by in situ anodisation of titanium in a single step process using potassium chromate as the chromium source. The morphology and structure were characterised by field emission scanning electron microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy. Optical properties were investigated by UV–Vis diffuse reflectance spectra. The visible light photocatalytic activity of the Cr–TiO₂ nanocomposite photoelectrodes was evaluated by measuring the degradation of rhodamine B dye under visible light irradiation. The results showed that Cr–TiO₂ nanocomposite electrodes have excellent photocatalytic performance. Cr–TiO₂ nanocomposite produced using 5 mM K₂CrO₄ exhibited better photocatalytic activity than did the pure TiO₂ and Cr–TiO₂ nanocomposite fabricated using other chromium concentrations. The anodisation process developed in this study is facile, reproducible and inexpensive and can be easily scaled up, thereby pioneering the fabrication of high performance photocatalysts with promising environmental applications.

Keywords:

• Nanocomposite
• Anodisation
• Photoelectrode
• Chromium