Engineering the Interfacial Contact between Bi₂WO₆and WO₃Heterojunction Photoanode for Improved Charge Transportation

Bi2WO6/WO3 heterojunction thin films with low or high interfacial contact between the Bi2WO6 and WO3 photocatalyst were employed as the photoanode for photoelectrochemical (PEC) reactions. By modulation of the transformation of WO3 to Bi2WO6 via a combined electrodeposition and hydrothermal reaction, a controlled degree of interfacial contact between Bi2WO6 and WO3 was achieved. An increase in the anodic photocurrent was observed from the PEC measurement, which was further supported by the conductive atomic force microscopy analysis under a low applied bias when the higher Bi2WO6/WO3 interfacial contact photoelectrode was examined. Experiment results suggested that the improvement was ascribed to a lower density of surface trap of the photoelectrons that reduced the charge recombination rate within the bulk photocatalyst.