High-Temperature Hydrogen Sensing Performance of Ni-Doped TiO₂ Prepared by Co-Precipitation Method

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• High-temperature hydrogen sensors are critical for combustion and industrial processing.
• Titanium dioxide (TiO2) is a promising material for gas sensing applications.
• Optimizing TiO2 properties through doping is essential for enhanced sensor performance.

Purpose of the Study:

• To synthesize and characterize undoped and nickel (Ni)-doped TiO2 nanoparticles.
• To investigate the effect of Ni doping on TiO2 morphology and phase composition.
• To evaluate the hydrogen (H2) sensing performance of Ni-doped TiO2 at high temperatures.

Main Methods:

• Co-precipitation method for nanoparticle synthesis.
• Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy for material characterization.
• Fabrication and testing of resistive sensors toward H2 at 600 °C.

Main Results:

• Nickel doping influenced the morphology and induced phase transitions in TiO2.
• 0.5% Ni-doped TiO2 exhibited an optimal anatase/rutile ratio.
• The 0.5% Ni-doped TiO2 sensor showed the best H2 response (ΔR/R0 = 72%), response rate, and selectivity.

Conclusions:

• 0.5% Ni-doped TiO2 demonstrates significantly improved H2 sensing capabilities at high temperatures.
• The enhanced performance is attributed to the increased formation of n-n junctions between anatase and rutile phases.
• This doping strategy offers a pathway for developing advanced high-temperature hydrogen sensors.