Preparation of the composite film based on CdS-modified TiO2 nanorod array with low density and its photoelectrochemical properties

Abstract

In order to increase the filling ratio of CdS photosensitized layer into the TiO2 array, a low-density TiO2 nanorod array with short-length rods and large rod-interval is prepared based on the TiO2 seed layer-coated FTO conductive glass through hydrothermal process. CdS seed layer is covered onto the TiO2 nanorod by chemical bath deposition. Then CdS photosensitized layer is grown in the TiO2 nanorod array via hydrothermal approach. SEM, XRD, UV-Vis absorption spectra are employed to characterize the TiO2/CdS composite films with different hydrothermal time of CdS. The photoelectrochemical properties of the TiO2/CdS composite film are also studied. The results indicate that the low-density of the TiO2 nanorod array could facilitate the infiltration of the CdS growth solution into the TiO2 array to form the perfect coverage with CdS seed layers. CdS photosensitized layers are homogeneously grown on the whole TiO2 nanorods and gradually filled in the TiO2 array through hydrothermal process. Meanwhile, flower-like CdS modified layers composed with short-length rods are formed at the top of composite film array. The light absorption of the TiO2 nanorod array is extended to the visible region with the CdS modification. The photocurrent of the TiO2/CdS composite film is obtained via 7 h hydrothermal growth of CdS layer. The excellent photoelctrochemical performance of the composite film of CdS modified TiO2 nanorod array with low density reveales its application prospect in solar cells.

Keywords

• electrochemistry
• TiO2 nanorod array with low density
• short rod-like CdS
• hydrothermal process
• photoelctrochemical property