TiO 2 nanotube arrays sensitized with CdS and CdSe for solar hydrogen production

Abstract

In this work we report investigation results of enhanced visible light photocatalytic properties of CdS and CdSe sensitized TiO 2 nanotube heterostructures. Anodically grown ordered TiO 2 nanotube arrays were sensitized with CdS and CdSe by using successive ionic layer adsorption and reaction method. Photocatalytic measurements revealed that heterostructured samples show enhanced photocurrent density under the visible light illumination. Improved visible light performance of the heterostuctures was explained by lower band gap of the CdS and CdSe and their favorable conduction band positions relative to TiO 2. Moreover, due to the lower band gap of the CdSe (1.7 eV) compared to CdS (2.4 eV), both photocurrent density and photoconversion efficiency results showed superior activity.