Electron-extracting system with enhanced photocatalytic hydrogen production performance: Synergistic utilization of Z-scheme and Ohmic heterojunctions

Low utilization of photogenerated electrons is usually caused by severe carrier recombination, being one of bottlenecks towards acquiring highly efficient photocatalytic hydrogen production system. Here, an artificial Z-scheme CuWO4/ZnIn2S4 heterojunction is integrated with NixP/ZnIn2S4 Ohmic contact to form a fascinating ternary-component system. The Z-scheme heterojunction can not only preserve excellent carrier separation and sunlight harvesting capability, but also markedly eliminate the photogenerated holes and improve the long-term photostability of ZnIn2S4. Additionally, the electrons can be further extracted from ZnIn2S4 to NixP due to the Ohmic contact, finally enhancing the utilization of photogenerated electrons, inhibiting the electron/hole recombination and prolonging the lifetime of photogenerated electrons. Benefiting from the synergistic effect of Z-scheme structure and Ohmic contact, the ternary system with excellent electron-extracting capacity exhibits 14-folds enhanced photocatalytic hydrogen evolution activity, compared to pure ZnIn2S4. This work may provide a valuable guideline in preparing highly efficient photocatalytic hydrogen production system.

Automated summary

By integrating an artificial Z-scheme structure and Ohmic contact, this study has successfully formed a ternary-component system, leading to increased utilization of photogenerated electrons, inhibition of carrier recombination, and prolonged lifetime of photogenerated electrons.