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

Abstract

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.

Structural, optical, and dielectric properties of hydrothermally synthesized SnO2 nanoparticles, Cu/SnO2, and Fe/SnO2 nanocomposites

“…Metal/metal oxide nanocomposites with excellent dielectric properties have received a lot of attention due to their widespread application [1][2][3][4]. For example, metal/SnO y nanocomposites (y = 1 or 2) were usually used in telecommunications, integrated circuits, high-frequency lithium batteries, supercapacitors, and solar cells [5][6][7][8]. Tin oxide (SnO 2 ) is an n-type semiconductor characterized by a wide band gap (∼3.6 eV) and electron mobility of 160 cm 2 V −1 s −1 at room temperature (RT) as a result of Sn interstitial defects and oxygen vacancies [9][10][11].…”

Layered Sol–Gel Deposition of a Sn, Ti, Zn, and Pr Mixed Oxide Thin Film with Electrical Properties for Gas Sensing

“…Nanocrystalline semiconductor metal oxides with controlled composition are of great interest in the field of gas sensors. Recently, many papers have been reported regarding the combination of SnO 2 , SiO 2 , In 2 O 3 , CeO 2 , TiO 2 , and ZnO to obtain materials with structural, optical, electrical, photocatalytic, and sensing properties [ 1 , 2 , 3 , 4 , 5 ].…”