Optimizing hydrogen evolution performance through balancing charge dynamics across sulfur-defect-engineered...

Area of Science:

• Materials Science
• Photocatalysis
• Green Energy

Background:

• Designing efficient photocatalysts is crucial for advancing photocatalysis.
• Understanding surface states and charge dynamics is key to optimizing photocatalytic hydrogen evolution (PHE).

Purpose of the Study:

• To fabricate a Schottky junction composite for enhanced PHE.
• To investigate the role of surface states and charge dynamics in PHE activity.

Main Methods:

• Fabrication of a sulfur-defect-engineered CdIn2S4 (CIS) combined with a hollow N-doped carbon (NC)-anchored MoC heterojunction.
• In-situ femtosecond transient absorption (fs-TA) spectroscopy to analyze charge carrier dynamics.
• Evaluation of photocatalytic hydrogen evolution rates under visible light.

Main Results:

• The optimal CdIn2S4/NC/MoC (25CIS-CM) composite exhibited a 58.2-fold enhancement in PHE rate compared to bare CIS.
• fs-TA measurements revealed that increased MoC loading reduced carrier relaxation and recombination times, up to an optimal point.
• Higher MoC loading (50CIS-CM) led to faster recombination and diminished PHE rates, indicating a critical balance is needed.

Conclusions:

• The fabricated Schottky junction composite significantly enhances photocatalytic hydrogen evolution.
• Optimizing the balance between charge trapping, interfacial migration, and recombination is essential for efficient photocatalysis.
• This study provides deeper insights into the photocatalytic mechanisms of CIS-based heterojunctions, promoting green energy technologies.