Novel Nanostructured WO₃@Prussian Blue Heterojunction Photoanodes for Efficient Photoelectrochemical Water Splitting

A simple hydrothermal method has been developed to prepare a WO3 nanorod array@Prussian blue (WO3@PB) composite material on FTO substrates with core–shell heterogeneous structures, aiming to enhance the limited photoelectrochemical performance of semiconductor nanomaterials. Due to their enhanced absorption efficiency, faster electron transfer rate, and more appropriate gradient energy gap structure, the obtained composite materials display higher photocurrent density in comparison with pure WO3. A photocurrent density of 0.34 mA/cm2 at 1.23 V vs RHE was finally obtained over a WO3@PB photoanode with an electrochemical deposition time of 150 s, which is 0.8 and 33 times higher than those of pure WO3 and PB, respectively. Our work offers a promising photoelectrocatalyst for water decomposition applications and provides a way for the synthesis of environmentally friendly and low-cost photoanode materials.