Mechanistic Insights Into In-Phase SrTiO₃(110)/ZnIn₂S₄(102) S-Scheme Heterojunctions for Multifunctional Hydrogen...

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Facet-engineered heterojunctions are key for advanced hydrogen evolution technologies.
• Sustainable hydrogen production requires efficient catalysts for photochemical, electrochemical, and photoelectrochemical processes.

Purpose of the Study:

• To synthesize and characterize in-phase SrTiO3(110)/ZnIn2S4(102) facet-rich heterojunctions.
• To investigate the charge transfer mechanisms and hydrogen evolution activity of these novel heterostructures.

Main Methods:

• Synthesis of SrTiO3/ZnIn2S4 heterojunctions.
• Structural and spectroscopic analyses (XPS, EIS, Mott-Schottky).
• Optical studies, electron localization function, and charge density mapping.

Main Results:

• An S-scheme charge transfer pathway was identified due to strong interfacial coupling and favorable band alignment.
• The heterojunctions exhibited enhanced charge separation and hydrogen evolution activity.
• Optimized 7.5 wt.% ZnIn2S4-SrTiO3 achieved a ~10-fold increase in photochemical H2 evolution and improved electrochemical/photoelectrochemical performance.

Conclusions:

• Facet-selective S-scheme design is crucial for efficient hydrogen production.
• Oxide-sulfide heterojunctions show great promise for scalable and sustainable hydrogen generation.
• The developed heterojunctions offer a cost-effective alternative without expensive substrates.