Interfacial Chemical Bond Engineering in a Direct Z-Scheme g-C3N4/ MoS2 Heterojunction

The Z-scheme heterojunction shows great potential in photocatalysis due to its superior carrier separation efficiency and strong photoredox properties. However, how to regulate the charge separation at the nanometric interface of heterostructures still remains a challenge. Here, we take g-C3N4 and MoS2 as models and design the Mo-N chemical bond, which connects exactly the CB of MoS2 and VB of g-C3N4. Thus, the Mo-N bond could act as an atomic-level interfacial bridge that provides a direct migration path of charge carriers between g-C3N4 and MoS2. Experiments confirmed that the Mo-N bond and the internal electric field promote greatly the photogenerated carrier separation. The optimized photocatalyst exhibits a high hydrogen evolution rate that is about 19.6 times that of the pristine bulk C3N4. This study demonstrates the key role of an atomic-level interfacial chemical bond design in heterojunctions and provides a new idea for the design of efficient catalytic heterojunctions.

Automated summary

The Z-scheme heterojunction is promising in photocatalysis due to its efficient carrier separation and strong photoredox properties. However, regulating charge separation at the nanometric interface remains a challenge. In this study, we used g-C3N4 and MoS2 as models and designed the Mo-N chemical bond to connect the CB of MoS2 and VB of g-C3N4. The Mo-N bond acts as an atomic-level interfacial bridge, facilitating charge carrier migration between g-C3N4 and MoS2. Experiments confirmed that the Mo-N bond and internal electric field greatly enhance photogenerated carrier separation. The optimized photocatalyst exhibits a hydrogen evolution rate 19.6 times higher than pristine bulk C3N4. This study demonstrates the importance of atomic-level interfacial chemical bond design in heterojunctions and provides a new approach for efficient catalytic heterojunction design.