The interest in the study of the formation mechanisms and the structure of electrical double layers (EDL) at oxide-electrolyte solution interfaces is predetermined by both the abundance of oxides in the nature and their use in practice. Recently, thin oxide layers (oxide nanostructures) have been increasingly applied for the production of highly active catalysts, ion-selective field-effect transistors, and other microelectronic devices. The method of molecular layer-by-layer deposition (MLD) from the gas phase allow one to produce one-and multicomponent element-oxygen nanostructures of different thicknesses on solid substrates [1-9]. Previously, we studied the electrosurface characteristics of one-component nanostructures synthesized on oxide substrates with the involvement of hydroxy and methoxy functional groups [10][11][12][13][14][15][16]. Data on electrosurface properties of composite (multicomponent) nanostructures are unavailable in the literature. Therefore, the goal of this work was the synthesis, study, and comparison of electrosurface properties of one-and two-component Al-and Ti-based nanostructures formed as films of different thicknesses on oxide substrates. In addition, colloidal characteristics of element-oxygen nanostructures of different compositions were compared with those of the substrates and corresponding bulk (hydr)oxides.One-and two-component nanostructures were synthesized with the involvement of hydroxy functional groups according to the following reactions (with the reference to a silica substrate):where E = Al or Ti.Samples were prepared in a flow of air, which was preliminarily dried over phosphorous oxide to a residual moisture content of 2 mg/m 3 . The dried air was saturated with either titanium chloride vapor or the vapor of solid aluminum chloride heated to 200°ë . After the excess of hydrogen chloride was removed with the dried air, the reaction product was treated with water vapor at 200°ë until HCl escaped from the reactor. In order to maintain a specified temperature in the reaction zone, a Nichrome wire was used, to which a necessary voltage was applied. The temperature was measured with a thermocouple.Aluminum-and titanium-oxygen nanostructures of different thicknesses, which were set by number n of the cycles of surface reactions (1) and (2), were synthesized on silicon oxide and aluminum hydroxide substrates. Hereafter, these structures are conventionally designated as n Al 2 O 3 / SiO 2 , n TiO 2 / AlOOH, and n TiO 2 /5 Al 2 O 3 / SiO 2 .Aerosil OX-50 (Degussa) (with a specific surface area S 0 = 42.5 m 2 /g, as determined by the BET method using the thermal desorption of argon with chromatographic recording) and a plane-parallel quartz capillary were used as silicon oxide substrates. The plane-parallel capillary was formed by the plates of KU quartz glass whose inner surfaces were preliminarily ground and polished (14th class). The size of asperities on SiO 2 plates did not exceed 0.1 µ m. Capillary length (5.8 cm) was determined by the geometric sizes of an initial pl...