An effective non-equivalent ion exchange method for building an advanced Z-scheme WO 3 /Bi 2 WO 6 photocatalyst

High contact quality is an essential factor for the effective transmission and separation of photocarriers for promoting the photo-induced redox reaction. In this study, a high contact quality Z-scheme WO 3 /Bi 2 WO 6 (WB) has been synthesized via a non-equivalent ion-exchange in situ growth method. The combination of inherent dipole (ID) of Bi 2 WO 6 and external built-in electric field (EBIEF) between WO 3 and Bi 2 WO 6 results in higher photocurrent density of WB and enhances the photo-redox reaction, thus overcoming the shortcomings of WO 3 and Bi 2 WO 6 . The apparent rate constant of WB-3 is 130 and 7 times higher than that of WO 3 and Bi 2 WO 6 , respectively, which benefits from the advantage of grain boundary for photogenerated carrier transfer which has no interface edge. This work provides an efficient method for developing an advanced Z-scheme photocatalyst with excellent performance.