Selective Hydrogen Sensing Using Fe₂O₃/TiO₂ Nanocomposites

The nanocomposites based on $\alpha $ -Fe₂O₃/TiO₂ nanocomposite were hydrothermally synthesized and characterized. A sensor device incorporating the nanocomposite was fabricated to assess its hydrogen ( ${\mathrm{H}}_{{2}}\text {)}$ gas sensing performance. Among the composites, Fe₂O₃/TiO₂ (10:1) showed the highest sensing signal (S) of 109.8, response with response time ( $T_{{90}}\text {)}~295$ s, and the recovery time ( $Tr_{{90}}\text {)}~97$ s for the H₂ concentration of 1000 ppm. When different concentrations of H₂ gas (15, 50, 100, and 1000 ppm) were used, a quick response time was obtained at 15 ppm H₂ concentration. For the interference study, a mixed gas composition of H₂ (100 ppm), NO₂ (10 ppm), CH₄ (100 ppm), and CO (100 ppm) was used to study the selectivity. The Fe₂O₃/TiO₂ (10:1) composite was found to have clear selectivity with a sharp sensing signal of 48.24, which was much higher than the rest of the signals.