Influence of Annealing Temperatures in Improving the Sensitivity of Pd modified WO3 nanoparticles based Hydrogen Sensor

The paper presents the influence of annealing temperatures on the sensing performance of Pd-modified WO
3
nanoparticles based hydrogen sensor. Pure and Pd modified Tungsten trioxide (WO
3
) sensors are synthesized using sol-gel deposition technique in the annealing temperature range of 500°C, 600°C and 700°C.The structural characterization of fabricated WO
3
sensors have been examined by the X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. The gas response characteristics of sensors have been studied towards different concentrations (0.01%, 0.05%, 0.1%, 0.5% and 1.0%) of hydrogen (H
2
) gas at various operating temperatures (150°C to 300°C). It has been examined that Pd modified WO
3
nanoparticles based hydrogen sensor shows lower operating temperature and higher response magnitude compare to pure WO3 nanoparticles based hydrogen sensor for the optimized annealing temperature of 600 °C. Pd modified WO
3
nanoparticles based hydrogen sensor with Pd–Ag (70%) contact is more suitable for the detection of H
2
gas compare to pure WO
3
nanoparticles based hydrogen senor.