Sergiienko S. The influence of additives of metal oxides on the structure, sensor and electrophysical properties of mesoporous materials based on tin dioxide

The thesis is devoted to influence of dopants (Si, In, Ti, Fe, V and Ce oxides) on the crystal and porous structure, nature of surface, sensor and electrophysical properties of mesoporous materials based on tin dioxide was studied. The influence of Si and In oxides additions on the electrochemical characteristics of electrodes for lithium power sources based on mesoporous tin oxide were investigated. The optimum composition of the initial film-forming sols and conditions of its heat treatment (duration and temperature of drying and calcination) for preparation of thin (~ 1 mm) layers of spatially ordered mesoporous tin dioxide with high adsorption characteristics were determined. It is shown that metal oxides (Si, In, Ti, Fe, V, Ce) doped materials based on mesoporous tin oxide substantially (by 2 - 10 times) changes sensor responses and significantly increases sensitivity to analytes of different nature (acids, bases, "small molecules", "oxidized", "carbon-rich" analytes, etc.). An approach for creating multisensor system that allows to analyze the gases and vapors of organic and inorganic compounds (ethanol, acetone, hexane, acetic acid, chlorobenzene, NH3, CH4, CO, H2, H2O) and to determine their concentrations in mixtures was proposed. It is shown that a combination of using of nonionic surfactant Pluronic-F127, ethanol media with low pH as well as Si oxide introduction allows to reduce the average size of the crystallites and to obtain mesoporous SnO2 samples with higher charge-discharge characteristics compared to microcrystalline tin dioxide.