Effects of copper and vanadium deposition in multi-walled hydrogen trititanate and mixed-phase anatase/trititanate nanotubes

Abstract

Metal incorporation and doping is one of the routes commonly explored to improve visible light photocatalytic activity of titania and related materials. In this work, we explore the effect of copper and vanadium deposition and incorporation in multi-walled hydrogen trititanate and mixed-phase anatase/trititanate nanotubes. The molecular designed dispersion method is used to introduce the metals in the materials. Electron paramagnetic resonance facilitates a full characterization of the metal sites before and after calcination and allows determining the UV- and visible-light-induced formation of paramagnetic intermediates. Vanadium or copper deposition on the tubes leads to increased formation of F⁺ centres under visible or UV illumination. The EPR results are linked to the activity towards rhodamine 6G photobleaching of the different materials.