SnO2-Based Porous Nanomaterials: Sol-Gel Formation and Gas-Sensing Application

Porous nanocomposites using two (tin dioxide-silica dioxide) and three (tin dioxide-indium oxide-silica dioxide)-component systems for gas sensors were created with the sol-gel method. To understand some of the physical-chemical processes that occurred during the adsorption of gas molecules on the surface of the produced nanostructures, two models-the Langmuir model and the Brunauer-Emmett-Teller theory-were used to carry out calculations. The results of the phase analysis concerning the interaction between the components during the formation of the nanostructures were obtained through the use of X-ray diffraction, thermogravimetric analysis, the Brunauer-Emmett-Teller technique (to determine the surface areas), the method of partial pressure diagrams in a wide range of temperatures and pressures and the results of the measurement of the nanocomposites' sensitivity. The analysis allowed us to find the optimal temperature for annealing nanocomposites. The introduction of a semiconductor additive into a two-component system based on tin and silica dioxides significantly increased the sensitivity of the nanostructured layers to reductional reagent gases.

Automated summary

Porous nanocomposites using two and three-component systems were created for gas sensors with the sol-gel method. The Langmuir model and the Brunauer-Emmett-Teller theory were used for calculations to understand the physical-chemical processes during gas adsorption. X-ray diffraction, thermogravimetric analysis, and other techniques were used to analyze the interaction between components and determine optimal annealing temperature. Introduction of a semiconductor additive increased the sensitivity of the nanostructured layers to reductional reagent gases.