Bi nanoparticles modified the WO3/ZnWO4 heterojunction for photoelectrochemical water splitting

The novel ternary photoanode was successfully prepared by Bi nanoparticles (Bi NPs) modified on type II het-erojunction of WO3-ZnWO4 using the simple and effective drop casting and chemical impregnation methods. The photoelectrochemical (PEC) experimental tests revealed that the photocurrent density of the ternary photoanode of WO3/ZnWO4(2)/Bi NPs reaches 3.0 mA/cm2 at 1.23 V (vs. RHE), which is 6 times of the WO3 photoanode. The incident photon-to-electron conversion efficiency (IPCE) at 380 nm wave length reaches 68%, which increases 2.8 times compared to WO3 photoanode. The observed enhancement can be attributed to the formation of type II heterojunction and modification of Bi NPs. The former broadens the absorption range for visible light and im-proves the carrier separation efficiency, while the latter enhances the light capture ability through the local surface plasmon resonance (LSPR) effect of Bi NPs and the generation of hot electrons.

Automated summary

The novel ternary photoanode was prepared by modifying Bi nanoparticles on the type II heterojunction of WO3-ZnWO4 using drop casting and chemical impregnation methods. The photocurrent density of the ternary photoanode reached 3.0 mA/cm2 at 1.23 V (vs. RHE), which is 6 times higher than the WO3 photoanode. The incident photon-to-electron conversion efficiency (IPCE) at 380 nm wavelength increased by 2.8 times compared to the WO3 photoanode, thanks to the formation of a type II heterojunction and the modification of Bi NPs, resulting in enhanced light capture ability and improved carrier separation efficiency.