Conductometric H₂S Sensors Based on TiO₂ Nanoparticles

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• High-performance hydrogen sulfide (H2S) sensors are critical for industrial safety and processes.
• Developing sensitive and reliable H2S sensors, especially for low concentrations, remains a significant research challenge.

Purpose of the Study:

• To investigate the potential of titanium dioxide (TiO2) as a conductometric sensor material for detecting low concentrations of H2S.
• To optimize TiO2 synthesis and annealing conditions for enhanced H2S sensing performance.

Main Methods:

• TiO2 synthesis via the sol-gel route, followed by annealing at 400°C and 600°C.
• Comprehensive material characterization using Scanning Electron Microscopy (SEM), Raman Spectroscopy, X-ray Diffraction (XRD), and FTIR Spectroscopy.
• Conductometric sensing tests to evaluate sensor response, selectivity, and kinetics for H2S detection.

Main Results:

• Characterization confirmed the formation of pure anatase TiO2, with increased crystallinity and particle size (11 nm to 51 nm) upon annealing at 600°C.
• Annealing at 600°C induced a phase transition to rutile and a slight decrease in band gap (3.31 eV to 3.26 eV).
• TiO2 annealed at 400°C exhibited optimal sensing performance, with a sensor response of ~3.3 at 2.5 ppm H2S and rapid response/recovery times of 8s and 23s, respectively.

Conclusions:

• TiO2 synthesized via sol-gel and annealed at 400°C demonstrates promising performance for low-concentration H2S detection.
• The material's properties, influenced by annealing temperature, are crucial for achieving high-performance H2S sensing.
• This study contributes to the development of advanced conductometric sensors for critical H2S monitoring applications.