Wafer-Scale Semitransparent MoS₂/WS₂ Heterojunction Catalyst on a Silicon Photocathode for Efficient Hydrogen...

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Developing optically transparent, electrically conductive, and protective catalysts is essential for efficient photoelectrochemical (PEC) hydrogen production.
• Simultaneously achieving these properties in catalysts for photoactive semiconductors presents significant challenges.

Purpose of the Study:

• To fabricate a wafer-scale transparent bilayer MoS₂/WS₂ catalyst with a staggered heterojunction for enhanced PEC hydrogen production.
• To optimize photon absorption, charge carrier extraction, and surface passivation of p-Si photocathodes.

Main Methods:

• Grown MoS₂ and WS₂ monolayers using metal-organic chemical vapor deposition.
• Sequentially transferred and stacked monolayers onto a p-Si photocathode.
• Fabricated a type-II heterojunction film for improved charge transport and surface protection.

Main Results:

• The MoS₂/WS₂/p-Si photocathode exhibited excellent PEC performance with a photocurrent density of -25 mA cm^-2 at 0 V vs RHE.
• The type-II heterojunction facilitated rapid charge carrier transport and protected the Si surface from degradation.
• Demonstrated enhanced stability compared to a monolayer MoS₂/p-Si system.

Conclusions:

• The developed transparent MoS₂/WS₂ bilayer catalyst offers a promising strategy for efficient PEC hydrogen production.
• This approach provides optically transparent, electrically active, and protective catalysts for practical energy conversion systems.
• Highlights the potential of staggered heterojunctions in advanced PEC applications.