Gallium Sulfide (Ga2S3) shows increased attention to research not only because of the relevant optical and photoelectrical properties of the material both in the polycrystalline and amorphous states, but also because it is a good molecular precursor for metal sulfides. As demonstrated by research in recent years Ga2S3 is a good material with highly applicative potential as passive contact layer in combination with GaAs [1]. In this context special attention is given to the capture properties on the Ga2S3 surface film of the gas from the environment. In this work, based on diffuse reflection spectrums FTIR, is investigated the absorption dynamics of the impurity air molecules from the atmosphere depending on the average size of Ga2S3 and Ga2S3 particles covered with proper oxide (Ga2O3). As shown by X-ray diffraction investigations, in the dispersion process of α-Ga2S3 with cubic crystal structure are occurring phase transformations of type α-γ. At the same time during this process is generated a high density of capture states for nonequilibrium electrical charges. Proper structural defects as well as those generated by mechanical dispersion of crystals covered with a proper nanocrystalline oxide layer are serving as centers of adsorption of molecules (especially, electric polarized) on the Ga2S3 and Ga2O3- Ga2S3 particles’ surface. Absorbed molecules on surface of Ga2S3 and Ga2S3-Ga2O3 nanoparticles interact intensively with infrared radiation in the domain of proper vibration. For the separation of the absorption properties of the nanostructures Ga2O3-Ga2S3 from the ones specific to the Ga2O3 oxide layer were separately studied the reflectance FTIR spectrums of the powders. Diffuse reflectance spectrum of Ga2O3 powder contains virtually only the spectrums of vibration and vibration rotation of the Ga-O and O-O bounds. In addition, vibration bands of Ga-O and O-O bounds are well pronounced also in the FTIR spectrums of Ga2S3 powder covered with proper oxide. On the surface of Ga2S3 proper oxide powder together with H2O molecules are intensively absorbed the CO molecules. These compounds contain bounds of the metal with oxygen atoms.Studies demonstrate the possibility to use Ga2S3 nanoparticles and Ga2S3-Ga2O3 nanostructures as effective receptors of molecules with proper electric pole or induced as a result of asymmetric vibrations of atoms components.