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.

Automated summary

Photoelectrochemical solar-driven hydrogen production using semiconductors as active materials shows promising potential, but faces challenges like limited absorption range and rapid charge recombination. This study constructs a photoelectrode based on a 0D/2D heterojunction using metal chalcogenide quantum dots and hierarchical Zn-MoS2 nanosheets. By analyzing the effects of different quantum dot materials on the nanosheets, the researchers found that the 0D/2D heterostructure based on the composite Zn-MoS2/PbS@CdS significantly enhances the photocurrent due to synergistic effects and improved light harvesting capabilities.