Electrochemical synthesis of coaxial TiO2–Ag nanowires and their application in photocatalytic water splitting

Abstract

A new method for the formation of coaxial TiO₂–Ag nanowires is presented, in which TiO₂ nanotubes were formed by the templated electrochemically induced sol–gel method, followed by thermal annealing. The as-formed TiO₂ nanotubes have been successfully filled with a Ag core using a subsequent electrodeposition step. Coaxial nanowires have a very suitable architecture for photocatalysis, solar cells or batteries due to the high contact area between the two different phases, the large outer surface area exposed to the reactant, and short electron diffusion paths. The coaxial nanowires showed a higher efficiency than empty TiO₂ nanotubes and TiO₂ nanotubes with attached Ag nanoparticles in photocatalytic water splitting. Coaxial TiO₂–Ag nanowires formed H₂ at a rate of ∼1.23 × 10⁻³ ± 0.3 × 10⁻³ mol g⁻¹ h⁻¹ without deactivation for at least 6 h.