Modulating the 0D/2D Interface of Hybrid Semiconductors for Enhanced Photoelectrochemical Performances

Photoelectrochemical (PEC) solar-driven hydrogen production is a promising route to convert solar energy into chemical energy using semiconductors as active materials. However, the performance is still far from satisfactory due to a limited absorption range and rapid charge recombination. Compared to 3D semiconductors, 0D/2D nanohybrids may exhibit better PEC performance, due to the formation of an intimate interface between the two semiconductors that can inhibit carrier recombination. Herein, a photoelectrode based on a 0D/2D heterojunction is constructed by 0D metal chalcogenide quantum dots (QDs) and hierarchical 2D Zn-MoS₂ nanosheets (NSs). The effect of PbS, CdS, and their composite PbS@CdS QDs is analyzed by depositing them onto Zn-MoS₂ NSs using an in situ process. This distinctive heterojunction can leverage the light harvesting capabilities of QDs with the catalytic performance of Zn-MoS₂ . Compared to Zn-MoS₂ , Zn-MoS₂ /PbS, and Zn-MoS₂ /CdS, the obtained 0D/2D heterostructure based on the composite Zn-MoS₂ /PbS@CdS has a significantly enhanced photocurrent. The synergistic effect between 0D/2D heterojunction, the extended absorption range of QDs, and the strong coupling and band alignment between them lead to superior solar-driven PEC performance. This work can provide a new platform to construct multifunctional 0D/2D nanohybrids for optoelectronic applications, not limited to PEC devices.