Highly Selective Room-Temperature Blue LED-Enhanced NO₂ Gas Sensors Based on ZnO-MoS₂-TiO₂ Heterostructures

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Developing highly selective and sensitive gas sensors for real-time monitoring is crucial.
• Ternary nanoheterostructures offer synergistic properties for enhanced performance.
• Room-temperature operation is desirable for energy efficiency and practical applications.

Purpose of the Study:

• To fabricate and characterize novel ternary zinc oxide-molybdenum disulfide-titanium dioxide (ZnO-MoS2-TiO2) nanoheterostructures for gas sensing.
• To evaluate the selectivity and sensitivity of these nanoheterostructures for nitrogen dioxide (NO2) detection at room temperature.
• To investigate the effect of light illumination on sensor performance.

Main Methods:

• Synthesis of ternary ZnO-MoS2-TiO2 nanoheterostructures.
• Characterization using SEM, EDX, Raman, and FTIR spectroscopy.
• Gas sensing measurements for NO2, NH3, CH4, and CO2 at room temperature.
• Evaluation of light-assisted enhancement using various LEDs.

Main Results:

• Successful fabrication of ternary ZnO-MoS2-TiO2 nanoheterostructures confirmed by comprehensive analyses.
• High selectivity and sensitivity towards NO2 at room temperature, with up to 58% sensitivity at 4 ppm.
• Short response time of approximately 0.51 min.
• Blue LED illumination significantly enhanced sensor responsiveness.

Conclusions:

• Ternary ZnO-MoS2-TiO2 nanoheterostructures represent a promising platform for highly sensitive and selective room-temperature NO2 gas sensors.
• These sensors are suitable for environmental monitoring, public health, and industrial process applications.
• Light-assisted sensing, particularly with blue light, can further improve sensor performance.