Synergistic effect of Cu doping and Z-scheme heterojunction on ZnIn2S4/Cu-doped WO3·0.5H2O for boosting photocatalytic H2 evolution

Abstract

The key to realizing efficient hydrogen production driven by sustainable solar is to develop high performance photocatalysts. Herein, a ZnIn2S4/Cu-doped WO3·0.5H2O (ZIS/Cu-WO) heterojunction was synthesized and the synergy between Cu doping and Z-scheme heterojunction in hydrogen production was explored. The synthesized (ZIS/Cu-WO) has a special octahedral structure. The doping of Cu ions can induce the localized surface plasmon resonance (LSPR) of WO3·0.5H2O, which extends the spectral response range and improves charge conduction. After growing ZnIn2S4 (ZIS), the optimal ZIS/Cu-WO photocatalyst shows a remarkable H2 production rate of 3084 μmolg-1h-1, which is 7.0 times than undoped ZnIn2S4/WO3·0.5H2O (ZIS/WO). The enhanced photocatalytic hydrogen production performance is attributed to the synergistic effect of Cu doping and Z-scheme heterojunction, which further accelerated the separation of photogenerated electron holes. Moreover, the Z-scheme photogenerated charge transfer mechanism was confirmed, and the ZIS/Cu-WO heterojunction exhibits superior stability in 16 h cycle test. This study provides a valuable reference in designing metal ion-doped heterojunction photocatalysts.