Optical H2 sensing performance of anodized nanoporous TiO2 thin films

Optical gas sensing performance of nanoporous TiO2 films coated with catalytic Pd layer was investigated for low concentration H2 sensing. Nanoporous TiO2 films were obtained from anodization of DC sputtered titanium (Ti). The Ti films were deposited onto quartz and subsequently anodized at room temperature and annealed at 800°C. Highly homogeneous arrays of nanopores having diameters in the range of 15-25nm were observed. It was found that the Pd/TiO2 nanoporous films show remarkable optical absorbance response towards H2 as low as 0.06%. The optimum operating temperature of the nanoporous films for H2 sensing was found to be very low (60°C).