Visible/solar-light driving photocatalytic activity of TiO₂ nanotubes upon coating with phosphotungstate hybrid

ABSTRACT

This study introduces coloured titanium dioxide nanotubes by phosphotungstate hybrid as an activated photocatalyst for the degradation of organic pollutants under visible and solar light irradiation. The prepared coloured TiO₂ nanotubes are characterised by Fourier transform infrared spectroscopy, powder X-ray diffraction, diffuse reflectance spectrometry, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy and N₂ adsorption–desorption isotherms. Then, performance of this catalyst is evaluated using decolourisation of model dyes methylene blue (MB), methyl orange (MO) and mixtures of MB and MO solutions. It is confirmed that the presence of coloured hybrid in the context of white TiO₂ enables photocatalytic activity in the visible and solar light. Also, its noticeable efficiency is verified in the photodegradation of organic dyes and its reusability without any significant loss of activity. Removal is via combination of adsorption and then photocatalytic degradation through oxidation by •OH radicals or reduction by reduced polyoxometalate. While the visible light is not able to degrade alone MO solution in the presence of composite, it degrades the MO mixed with MB solution.

KEYWORDS:

• Titanium dioxide nanotubes
• nanophotocatalyst
• polyoxometalate
• dyes

Disclosure statement

No potential conflict of interest was reported by the authors.

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