Boosted Solar Water Splitting over Direct S-Scheme Sulfur-Deficient ZnIn₂S₄/1D TiO₂ Nanoarrays

Area of Science:

• Materials Science
• Nanotechnology
• Photocatalysis

Background:

• S-scheme defect-engineered heterojunctions (S-DEH) offer enhanced carrier separation and electron transport in hybrid nanocatalysts.
• Efficient solar-fuel production and eco-friendly energy evolution are critical global challenges.

Purpose of the Study:

• To fabricate visible-light-responsive sulfur-deficient ZnIn2S4 quantum dots/TiO2 nanoarrays (TAs/S_V-ZIS) for improved photocatalytic water splitting.
• To investigate the role of defect engineering and heterojunction formation in enhancing photocatalytic activity.

Main Methods:

• Synthesis of sulfur-deficient ZnIn2S4 quantum dots and their integration with TiO2 nanoarrays.
• Characterization of the fabricated TAs/S_V-ZIS nanocomposites.
• Evaluation of photocatalytic hydrogen production rates under simulated solar irradiation.

Main Results:

• The TAs/S_V-ZIS exhibited a direct S-DEH system driven by matched band gaps, interfacial bonds, and built-in electric fields.
• The optimized TAs/S_V-ZIS achieved a hydrogen production rate of 72.475 mmol·h−1·g−1.
• This rate is approximately 3.9 times higher than pristine TiO2 nanoarrays and 2.0 times higher than TAs/ZIS.

Conclusions:

• The defect engineering in TAs/S_V-ZIS effectively enhances charge transport, carrier separation, and electron lifetime.
• The fabricated S-DEH system demonstrates significant potential for efficient solar-fuel production through water splitting.
• This work provides a promising strategy for developing advanced photocatalysts for sustainable energy applications.