MoS₂/CdS Heterojunction with High Photoelectrochemical Activity for H₂ Evolution under Visible Light: The Role of MoS₂

Abstract

MoS 2 /CdS p-n heterojunction films with high photoelectrochemical activity for H 2 evolution under visible light were successfully prepared by electrodeposition followed by chemical bath deposition. The films were characterized by X-ray diffraction, scanning electron microscopy, UV−visible absorption, X-ray photoemission spectroscopy, photoluminescence, and photoelectrochemical response. The MoS 2 /CdS heterostructure shows much higher visible-light photoelectrocatalytic activity and higher stability toward the water splitting than pure CdS film. The MoS 2 /CdS film with an optimal ratio of 0.14% exhibits the highest photocurrent of 28 mA/cm 2 and the highest IPCE of ca. 28% at 420 nm at 0 V vs Ag/ AgCl. The critical role of MoS 2 in the MoS 2 /CdS film was investigated. The improved photoelectrochemical performance of the MoS 2 /CdS heterojunction film was attributed to the visible light absorption enhanced by MoS 2 and the formation of a p-n junction between CdS and MoS 2 , which accelerates the effective separation of photogenerated carriers by the internal electrostatic field in the junction region.

Layer-controlled growth of MoS2 on self-assembled flower-like Bi2S3 for enhanced photocatalysis under visible light irradiation

“…One effective way to enhance band bending is to create a thermodynamically driven heterojunction by incorporating another semiconductor, depending on the favored band offsets between the two semiconductors. 6 Generally, the semiconductor that is incorporated as a cocatalyst to construct such a self-established heterojunction should possess good electric conductivity, a suitable energy structure and excellent electrochemical activity. [7][8][9][10][11] As a typical layered metal sulfide, MoS 2 has drawn increasing attention because of its layered structure similar to that of graphene, which is composed of three atom layers stacked together through Van der Waals interactions.…”

Two-dimensional transition metal dichalcogenide nanomaterials for solar water splitting

“…Furthermore, the absorption spectra of MoS 2 /CdS also improved due to the small band of MoS 2 . [103] Therefore, an excellent synergetic effect of MoS 2 with CdS results in a highly improved PEC performance.…”

Emerging Energy Applications of Two-Dimensional Layered Materials

“…Further details on the mechanism need to include crystallinity and identification of active sites and the effect of strain in the 1T phase on HER performance should be clarified 231,232,234,[236][237][238][239][240][241][242][243][244][245][246][247][248][249] . The knowledge gained then needs to be successfully transferred to the development of new TMDCs structures or engineered surfaces for maximizing HER performance.…”