Sonication-assisted synthesis of CdS quantum-dot-sensitized TiO₂ nanotube arrays with enhanced photoelectrochemical and photocatalytic activity

A sonication-assisted sequential chemical bath deposition (S-CBD) approach is presented to uniformly decorate CdS quantum dots (QDs) on self-organized TiO₂ nanotube arrays (TNTAs). This approach avoids the clogging of CdS QDs at the TiO₂ nanotube mouth and promotes the deposition of CdS QDs into the nanotubes as well as on the tube walls. The photoelectrochemical and photocatalytic properties of the resulting CdS-decorated TNTAs were explored in detail. In comparison with a classical S-CBD approach, the sonication-assisted technique showed much enhancement in the photoelectrochemical and photocatalytic activities of the CdS QDs-sensitized TNTAs.