Visible Light-Driven Heterojunction Array Based on Type-I In₂S₃/In₂O₃ for Selective Multi-Gas Discrimination

Area of Science:

• Materials Science
• Chemical Sensing
• Nanotechnology

Background:

• Visible light-activated chemoresistive gas sensors offer low power consumption and room temperature operation.
• Challenges include slow recovery, reduced sensitivity to NO2, and difficulty detecting VOCs and amines under visible light.

Purpose of the Study:

• To develop a visible light-driven gas sensor array with enhanced performance.
• To achieve selective detection of multiple gases using a novel heterostructure.

Main Methods:

• Fabrication of a type-I In2S3/In2O3 heterostructure by depositing In2S3 on In2O3 nanorods.
• Utilizing blue light illumination to drive the gas sensing mechanism.
• Decorating the heterostructure with noble metals (Pd, Pt, Au) for enhanced selectivity.

Main Results:

• The In2S3/In2O3 heterostructure exhibited a 56-fold increase in NO2 response compared to pristine In2O3.
• The sensor demonstrated excellent selectivity, reliability, and humidity stability for NO2 detection.
• Noble metal decoration enabled selective detection of NO2, NH3, C2H5OH, and H2.

Conclusions:

• The type-I In2S3/In2O3 heterostructure effectively enhances visible light-driven gas sensing.
• This approach offers a new strategy for optimizing light-activated gas sensors and advancing electronic nose technologies.