Efficient charge carrier separation and enhanced UV–visible photocatalytic activity in macroporous TiO<inf>2</inf> decorated with V<inf>2</inf>O<inf>5</inf>/Ag nanostructures

We report a novel structure – macroporous TiO2 decorated with V2O5/Ag nanoparticles – for enhanced visible photocatalytic activity by efficient charge carrier separation and enhanced visible light absorption. They are found to be much superior to TiO2∕V2O5, TiO2/Ag and V2O5/Ag composite particles. V2O5 particles are found to reduce the recombination of photogenerated carriers from TiO2 under UV exposure by charge transfer mechanism along with the increased absorption in the visible region. Further decoration with Ag nanoparticles enables efficient absorption of light over the visible region due to the localized surface plasmon resonance. In addition, Ag nanoparticles act as effective electron traps for the photogenerated electrons from V2O5 and enhances the photocatalytic activity in the visible region. Rate constant values obtained for TiO2∕V2O5 and TiO2∕V2O5/Ag heterostructures are 0.009 and 0.014 min−1 respectively. Heterostructures are also found to be recyclable in nature making them highly suitable for visible photocatalytic applications.