Synthesis of Coupled Semiconductor by Filling 1D TiO2 Nanotubes with CdS

A Coupled semiconductor material is prepared by filling one-dimensional (ID) titania (TiO2) nanotubes (NTs) with cadmium sulfide (CdS) nanoparticles (NPs). Self-assembled TiO2 NTs (length = 550 nm, diameter = 80 nm) are prepared by the sonoelectrochemical anodization method. These NTs are functionalized with US NPs by a single-step electrodeposition method. This material harvests solar light in UV as well as visible light (up to 510 nm) region. An eight to 9-fold enhancement in photoactivity is observed using US functionalized TiO2 NTs compared to pure TiO2 NTs and commercial P25 NPs. This methodology will be useful in designing multijunction semiconductor materials confined inside ID nanochannels.