Atomic Layer Deposition of TiO₂ Nanocoatings on ZnO Nanowires for Improved Photocatalytic Stability

Figure 1

(a) Water splitting cell: incident light creates photogenerated electron-hole pairs. Given an appropriate band structure (straddling water reduction/oxidation potentials), holes and electrons will oxidize water at the photoanode and reduce resulting H⁺ ions at the cathode, respectively. These reactions result in oxygen and hydrogen gas production. (b) Proposed band gap structure of TiO₂@ZnO: high-aspect ratio TiO₂ experiences charge separation at the electrolyte-TiO₂ interface, moving holes into the electrolyte and electrons into the single-crystalline ZnO nanowire.

(a)

(b)