Optical diagnostics of physicochemical properties of NiO/AlO nanocomposites upon exposure to different gases and heat.

Khairullina, A.; Parkhomenko, I.; Kudanovich, O.; Filimonenko, D.

We have studied nanostructural and optical properties of composites of nanostructured nickel oxide films on a substrate from porous aluminum oxide NiO/AlO in the UV, visible, and IR spectral ranges on exposure of composites to different gases, vacuum, and heat. We have found that, upon irradiation of NiO/AlO composites by laser radiation at a wavelength of 633 nm, they demonstrate a high sensitivity to carbon monoxide CO in the range of the excitonic absorption of nickel oxide. We assume that an increase in the transmission coefficient of the composite in the excitonic absorption band is determined by luminescence that is caused by the oxidation reaction of carbon monoxide. The sensitivity of composites to CO is enhanced with decreasing the size of NiO nanoparticles and after evacuation. The values of the diffuse reflection coefficient at the laser radiation wavelength of 633 nm correlate with the size of nickel oxide nanoparticles. Spectral changes in the range of the fundamental absorption band of NiO that occur in the IR range and in diffuse reflection spectra are related to the appearance of carbon-containing compounds in the composite exposed to CO.

NANOCOMPOSITE materials; ALUMINUM oxide; OPTICAL properties of metals; NICKEL films; ULTRAVIOLET radiation; INFRARED spectra; METAL nanoparticles

Optics & Spectroscopy, 2012, Vol 112, Issue 5, p713

0030-400X

Academic Journal

10.1134/S0030400X12050086