Insertion of nanostructured titanates into the pores of an anodised TiO2 nanotube array by mechanically stimulated electrophoretic deposition

Abstract

TiO₂ nanotube (TiO₂NT) surfaces can achieve a high area surface and enhanced electrocatalytic properties. One of the key challenges is the insertion of nanostructured titanates deeply into the pores of TiO₂NT. We describe the electrophoretic deposition (EPD) of two different titanates - nanosheets (TiNSs) and nanotubes (TiNTs) into the pores of TiO₂NT to produce controlled hierarchical surfaces. A sufficiently high applied cell potential and mechanical stimulation of the surface are important to incorporate TiNSs and TiNTs inside the pores of TiO₂NTs. The electrodes show improved hydrophobicity after deposition of titanates. The beneficial effect of a counter electrode equipped with a brush to avoid the accumulation of a thick outer layer on TiO2NTs is highlighted.