Photoelectrochemical performance of CdS nanorods grafted vertically aligned TiO2 nanorods

•TiO2 nanorods/CdS nanorods composite samples were successfully achieved.•The photocurrent density increased by 100 percent compared with pure TiO2.•Photocurrent density increase mechanism of this photoanode was also forecasted.

In this study, TiO2 nanorods/CdS nanorods composite samples were successfully synthesized by grafting CdS nanorods on vertically aligned TiO2 nanorods. A two-step hydrothermal method was used to prepare the samples. Some properties of the samples, such as morphological, structural, and optical properties were characterized by energy-dispersive X-ray detection, field emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and ultraviolet-visible spectroscopy. Moreover, photoelectrochemical properties were studied via current-voltage and photocurrent spectrum measurements. The results showed that CdS nanorods grafted on top of TiO2 nanorods like a lawn. The amount grafted as well as the diameter and crystallinity of CdS nanorods increased first and then decreased as the grafting time increased, due to Ostwald ripening. Under the back-side illumination, the composite film with 2 h grafting time exhibited the highest photocurrent density which was almost twice of that of the pure TiO2 nanorods.

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