Photocatalytic degradation of methylene blue dye on reticulated vitreous carbon decorated with electrophoretically deposited TiO2 nanotubes

Abstract

Titanate nanotubes (TiNT) were deposited over the surface of 100 pores per inch (ppi) reticulated vitreous carbon (RVC) by anodic electrophoresis at a cell voltage of 15 V, in an undivided cell, from an ethanol/water suspension containing TiNT coated with tetrabutylammonium hydroxide (TBAOH) surfactant. Scanning electron microscopy showed the open cell porous structure of TiNT/RVC coated by a uniform ca. 30 mu m thick layer of TiNT. Calcination at 450 degrees C for 2 h in air improved the photocatalytic properties. The material was used as photocatalyst for the decolourisation of methylene blue (MB) dye. The 98% volumetric porosity of the RVC substrate provided good reactant access and large surface area for deposition of TiNT. The calcined TiNT/RVC substrate achieved a 91% dye degradation after 20 min, which was higher than uncoated, acid treated RVC and non-calcined TiNT/RVC substrate. The MB decolourisation improved at an increased thickness of 3D TiNT/RVC catalyst although the improvement was limited to 4 mm on 100 ppi RVC due to limited UV penetration.