CdS/TNRs/TNTs were synthesized by combining a hydrothermal method with a sequential-chemical bath deposition method and displayed enhanced visible light-induced photoelectrocatalytic hydrogen production activity compared with TNTs, TNRs/TNTs and CdS/TNTs.
A novel CdS/TiO 2 nanorods/TiO 2 nanotube array (CdS/TNRs/TNT) photocatalyst was prepared. The self-organized highly oriented TiO 2 nanotube arrays (TNTs) were first synthesized by anodizing Ti sheets. The “flower-like” rutile TiO 2 nanorods (TNRs) were then grafted on the TNTs by a hydrothermal method. Subsequently, the CdS quantum dots (CdS QDs) were deposited on the surface of the resulting TNRs/TNTs using a sequential-chemical bath deposition (S-CBD) method. UV-vis diffuse reflectance spectra indicated that the CdS/TNRs/TNTs sample showed significantly enhanced absorption in the range from 350 to 700 nm. The photoelectrocatalytic hydrogen production activities of all samples were evaluated by using Na 2S and Na 2SO 3 as sacrificial reagents in water under a 300 W Xe lamp with a UV-light filter ( λ > 420 nm). The results showed that CdS/TNRs/TNTs prepared by hydrothermal reactions for 4 h and S-CBD 15 cycles showed a hydrogen production rate approximately 14 times that of the TNTs. When compared to CdS/TNTs, CdS/TNRs/TNTs showed a 2.3 fold increase in hydrogen production, which can be attributed to the enlarged effective deposition area for CdS QDs by depositing “flower-like” rutile TiO 2 nanorods on the TNTs. In addition, CdS/TNRs/TNTs exhibited excellent hydrogen production stability using Na 2S and Na 2SO 3 as sacrificial reagents.