Interfacial rectification effect in CdS-based cascade dual heterojunction for enhancing cooperative coupling of hydrogen peroxide production and organic synthesis

Abstract

Poor charge separation efficiency is the main dilemma of achieving satisfying H₂O₂ production performance. Despite the fact that most single-side modulation is achieved through either electron or hole transfer, concerns persist regarding the limited charge transfer efficiency and material stability. Beyond this conventional thinking, a S-scheme heterojunction MoS₂/CdS@CdMOF (CMM) core–shell structure has been successfully prepared, facilitating efficient carrier escape from the perishable CdS. As a result, we observed significant enhancements in both H₂O₂ production (43.31 mmol g⁻¹ h⁻¹) and benzaldehyde formation rate (44.23 mmol g⁻¹ h⁻¹) as well as stability, which is 10 times that of CdS. Relevant research findings have demonstrated that the compact heterojunction experiences interface lattice expansion and surface compression. Thus, the Cd–O bond within the interface functions as an electron bridge, substantially improving the efficiency of charge separation. Moreover, the compressed surface configuration of MoS₂ mitigates tension to facilitate polarization of oxygen molecules and exchange of carriers, thereby decreasing the activation energy of the reaction and promoting molecular activation. This research has the capability to improve our comprehension of charge separation at interfaces and offer valuable perspectives for the progress of S-scheme heterojunctions with improved efficiency.