Hydrothermal synthesis of the CdS nanorods on electrochemically deposited Fe2O3 thin film for improving photoelectrochemical performance

In this study, a CdS nanorod layer is hydrothermally synthesized on an electrochemically deposited Fe2O3 thin film substrate. These two components are hierarchically stacked to form a type-II heterojunction for enhancing photoelectrochemical performance. The Fe2O3/CdS composite photoanode system shows enhanced photocurrent density (1724 μA·cm−2 at 1.23 VRHE), incident photon-to-current conversion efficiency (23.3% at 390 nm), applied bias photon-to-current conversion efficiency (0.48% at 0.68 VRHE), electron lifetime, reduced charge transfer resistance, and good stability in an alkaline solution. It also has enhanced optical absorbance compared to the Fe2O3 and CdS only samples. The optical band gap of the composite Fe2O3/CdS system is narrowed by adding the Fe2O3 component to the CdS nanorod layer. Therefore, the underlying Fe2O3 layer plays a significant role in transferring charges through the CdS nanorod layer in this photoelectrochemical cell system.