Sensing mechanism of ethanol and acetone at room temperature by SnO₂ nano-columns synthesized by aerosol routes: theoretical calculations compared to experimental results

Abstract

A useful feedback loop: insights from theoretical calculations are used for rational design of nanosensors and for elucidating surface interactions.

Printable Fabrication of a Fully Integrated and Self‐Powered Sensor System on Plastic Substrates

“…A typical XRD pattern of a printed SnO 2 layer with the as‐prepared ink is shown in Figure a, with dominant peaks at 26.49°, 33.75°, and 51.74° corresponding to (110), (101), and (211), indicating the tetragonal rutile phase of SnO 2 nanoparticles. Notably, it has been reported that the adsorption of ethanol and acetone on surface facets of (110) and (101) is thermodynamically favorable, and thus the as‐printed SnO 2 thin films is suitable for gas detection . As shown in the SEM and EDS images (Figure b,c; Figure S9, Supporting Information), the inkjet printed SnO 2 layer is uniform and continuously bridges the Ag integrated electrodes with an electrode width of 50 µm and interspace of 100 µm.…”

“…SnO 2 as a n‐type semiconductor, is one of the most commonly used material for gas sensing mainly due to its low cost, stability, and repeatability . While metal oxide sensors normally require high operation temperature (over 200 °C) to achieve high sensitivity and fast recovery, recent studies demonstrated the SnO 2 has the capability for volatile organic compounds detection under room temperature, which eliminate the integration of heaters and thermal isolation units . Especially for portable and wearable electronics, room temperature operational sensors are highly desirable for device miniaturization and long cruising time without extra power consumption for heaters .…”

“…The resistances ( R ) of sensors were continuously monitored, and more details can be found in the Experimental Section. According to the ionosorption mechanism, when the sensors are initially exposed to dry air, oxygen molecules adsorb on the surface of SnO 2 and capture free electrons . These electrons will then be released back to SnO 2 when reduction gas (e.g., ethanol, acetone) is introduced into the system and interacts with oxygen species.…”

“…As shown in Figure f, the fully printed SnO 2 sensors delivered a sensitivity of 13.2% to 1.54 vt % of ethanol, and 3.1% to 6.07 vt % of acetone. Notably, due to the fact that the hydroxyl group has stronger interact with SnO 2 surface, the sensors show higher sensitivity to ethanol while superior recovery performances are observed as for acetone detection.…”

A highly sensitive gas sensor employing biomorphic SnO2with multi-level tubes/pores structure: bio-templated from waste of flax

“…Semiconducting metal oxide-based gas sensors have aroused signicant research interest owing to their low cost, easy production and high sensitivity, stability, and scalability. [1][2][3][4][5] They are broadly applied in elds ranging from health monitoring and medical detection to safety. 3,[6][7][8] Among the currently available metal oxide semiconductors, SnO 2 , as a typical n-type semiconductor with a 3.6 eV band gap, has been extensively studied in the eld of gas sensors and applied to the detection of a number of different gases such as HCHO, CH 3 OH, NH 3 , C 2 H 6 O, CO, SO 2 , CH 4 and H 2 S. 6,[9][10][11][12][13][14] However, the practical applications of SnO 2 have been limited due to its low selectivity, high operating temperature and unsatisfactory sensing response.…”