Synthesis and characterization of TiO2/CdS core–shell nanorod arrays and their photoelectrochemical property

TiO2/CdS core–shell nanorod arrays have been fabricated via a two-step method. Vertically aligned TiO2 nanorod arrays (NRs) were synthesized by a facile hydrothermal method, and followed by depositing CdS nanoparticles on TiO2 NRs by spin-coating successive ion layer adsorption and reaction (spin-SILAR) method. The surface morphology, structure, optical and photoelectrochemical behaviors of the core–shell NRs films are considered. The UV–vis absorption spectrum results suggested that the absorption peak of the TiO2/CdS core–shell NRs shifts from the ultraviolet region to the visible region in comparison to that of the pure TiO2 NRs. The obviously enhanced photoelectrochemical (PEC) performances of the heterojunction NRs were found under illumination of the simulated sunlight in comparison with that of the TiO2 NRs. The enhanced PEC performance and formation mechanism of TiO2/CdS core–shell NRs were discussed in detail.

► TiO2/CdS core–shell nanorod arrays were fabricated by spin-SILAR method. ► The enhanced photocurrent was found in the TiO2/CdS core–shell nanorod arrays. ► The CdS coated on TiO2 increases the e-h separation and enlarges light absorption range.