It was studied how the conditions of heat treatment of a [Zn(H2O)(O2C5H7)(2)] solution in isoamyl alcohol at 120-140A degrees C for 2-60 min affect the precursor decomposition mechanism and the characteristics of the obtained nanocrystalline zinc oxide. In all the cases, the product was a crystalline substance with the wurtzite structure and a size of crystallites of 14-18 nm, which was independent of the synthesis conditions. The thermal behavior and microstructure of the separated and dried nanostructured ZnO powder were investigated. It was determined how the duration and temperature of the heat treatment of the precursor solution affects the microstructure of ZnO coatings dip-coated onto glass substrates using dispersions produced at 120 and 140A degrees C. The nanosized ZnO application procedure was shown to be promising for creating a gas-sensing layer of chemical gas sensors for detecting 1% H-2 ( was 58 +/- 2 at an operating temperature of 300A degrees C) and 4 ppm NO2 ( were 15 +/- 1 and 1.9 +/- 0.1 at operating temperatures of 200 and 300A degrees C, respectively).