Humidity-resistant triethylamine sensor based on Cu-doped CdIn₂S₄ nanoflowers

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Bimetallic sulfides are promising for low-power gas sensing but suffer from poor humidity tolerance and slow kinetics.
• Cadmium indium tetrasulfide (CdIn2S4) is a potential candidate, but its performance needs improvement for practical use.

Purpose of the Study:

• To enhance the gas sensing properties of CdIn2S4 by introducing sulfur vacancies through copper (Cu) doping.
• To investigate the effect of Cu doping on the electronic structure and gas sensing performance of CdIn2S4 for triethylamine detection.

Main Methods:

• Synthesis of Cu-doped CdIn2S4 (Cu-CdIn2S4) material.
• Gas sensing measurements of Cu-CdIn2S4 and pristine CdIn2S4 towards triethylamine.
• Analysis of material properties, including specific surface area and sulfur vacancy concentration.

Main Results:

• Cu-CdIn2S4 demonstrated a significantly enhanced response (21) to 100 ppm triethylamine at 100°C, five times higher than CdIn2S4.
• The sensor achieved a low detection limit of 100 ppb with rapid response (2 s) and recovery (33 s) times.
• The doped material exhibited excellent humidity resistance and selectivity.

Conclusions:

• Copper doping effectively modifies the electronic structure of CdIn2S4, increasing sulfur vacancies and specific surface area.
• These modifications accelerate gas-target interaction kinetics, leading to superior gas sensing performance.
• Defect-engineered Cu-CdIn2S4 presents a cost-effective and highly responsive material for low-power triethylamine detection.