Boosted electron-transfer by coupling Ag and Z-scheme heterostructures in CdSe-Ag-WO3-Ag for excellent photocatalytic H2 evolution with simultaneous degradation

Coupling the heterojunction system with surface plasmon resonance (SPR) effect is an innovative and feasible strategy to improve photocatalyst. An excellent Z-scheme CdSe-Ag-WO3-Ag photocatalyst was constructed via continuous photo-assisted process, which exhibited superior photocatalytic activity in H-2 evolution (448.31 mu mol.g(-1) for 4 h) with simultaneous degradation of CFZ (96.32% in just 30 min) compared with CdSe-WO3, CdSe and WO3. This developed system conforms to Z-scheme electron transfer mode: CB/WO3 to Ag NPs, Ag NPs to VB/CdSe. It was verified by experiments, DFT simulation and in situ XPS characterization. So the strong reducing electron in CB/CdSe and the strong oxidizing hole in VB/WO3 were retained for H-2 evolution and degradation, respectively. The coupling Ag with Z-scheme heterojunction can realize rapid electron transfer and utilization. Because the Z-scheme heterojunction inhibits recombination of carriers of the single catalyst itself and enhances electrons life, Ag acts as conductive channel to accelerate electrons transfer, and the surface defects of CdSe and Schottky barrier reduce the energy loss during the electron transmission process. This work provides new insights for boosts electron transfer to improve photocatalytic performance.

Automated summary

Combining heterojunction systems with surface plasmon resonance (SPR) effect is an innovative and feasible strategy to improve photocatalysts. The constructed Z-scheme CdSe-Ag-WO3-Ag photocatalyst exhibits superior photocatalytic activity in H-2 evolution and CFZ degradation, with silver acting as a conductive channel to accelerate electron transfer and reduce energy loss. This work provides new insights for enhancing electron transfer to improve photocatalytic performance.