Thermally Stable SnO₂ Nanocrystals: Synthesis and Application to Gas Sensors

Abstract

We prepared the thermally stable SnO 2 nanocrystals (ca. 4 nm) in the mixture of SnCl 4 , tetraethylene glycol (TEG) and a tetrabutyl ammoniumhydroxide (TBAH) under refluxing and obtained a highly sensitive semiconductor gas sensor. It has been elucidated theoretically and experimentally that the synthesis of oxide semiconductor nanoparticles is an important factor for the highly sensitive semiconductor gas sensor. However, as-synthesized nanocrystals generally grow in large size during calcination at high temperature. Such a thermal growth of crystals reduces the sensor response. Therefore, to develop the sensor response of semiconductor gas sensor, thermally stable SnO 2 nanocrystals were synthesized via the heating of SnCl 4 -TBAH-TEG mixture up to 200 o C under refluxing. The SnO 2 nanocrystals obtained exhibited highly thermal stability even if they were calcined.The gas sensing films fabricated from the thermally stable SnO 2 nanocrystals exhibited high sensor response to hydrogen due to their small crystalline size, small donor density and change in the surface property as compared to the conventional SnO 2 nanocrystals via hydrothermal treatment.

Synthesis of Cu2O/CuO Nanocrystals and Their Application to H2S Sensing

“…This effect is explained in terms of the effective formation of electron-depleted regions in nanosized crystals by oxygen adsorption, which induces a significant change in electrical conductivity upon gas reaction [13,14]. Thus, the use of oxide nanoparticles and nanocrystals is one of the most efficient ways to develop high-performance gas sensors [15,16]. There have been many reports on the gas sensing properties of CuO nanoparticles deposited on other semiconductors such as SnO 2 [17], ZnO [18], graphene oxide [19].…”

Synthesis and gas sensing properties of molybdenum oxide modified tungsten oxide microstructures for ppb-level hydrogen sulphide detection

“…7 Up to now, a large number of metal oxide semiconductors such as SnO 2 , ZnO, Fe 2 O 3 , In 2 O 3 , NiO, and WO 3 (ref. [8][9][10][11][12][13][14][15] have been widely used as gas sensing materials because of their tunable dimension and structures.…”

Single step facile synthesis of Cu-SnO2/ZnO nanocomposite photocatalyst for methylene blue dye degradation in aqueous solution

“…Tin dioxide (SnO 2 ) is an n-type direct band gap semiconductor with a rutile tetragonal structure and outstanding properties due to a large exciton binding energy, electrocatalyst [1], strong adsorption capacity [2], high carrier mobility [3], high thermal stability [4,5], high photosensitivity [6], high abundance, inexpensive and low toxicity. Phil et al 2016 and Pham Van Viet et al 2016, report SnO 2 nanoparticles with higher photocatalytic degradation efficiency of a methylene blue dye than a bulk [7,8].…”