Enhancing Formaldehyde Selectivity of SnO2 Gas Sensors with the ZSM-5 Modified Layers

Abstract

High performance formaldehyde gas sensors are widely needed for indoor air quality monitoring. A modified layer of zeolite on the surface of metal oxide semiconductors results in selectivity improvement to formaldehyde as gas sensors. However, there is insufficient knowledge on how the thickness of the zeolite layer affects the gas sensing properties. In this paper, ZSM-5 zeolite films were coated on the surface of the SnO2 gas sensors by the screen printing method. The thickness of ZSM-5 zeolite films was controlled by adjusting the numbers of screen printing layers. The influence of ZSM-5 film thickness on the performance of ZSM-5/SnO2 gas sensors was studied. The results showed that the ZSM-5/SnO2 gas sensors with a thickness of 19.5 μm greatly improved the selectivity to formaldehyde, and reduced the response to ethanol, acetone and benzene at 350 °C. The mechanism of the selectivity improvement to formaldehyde of the sensors was discussed.

Au- and Pd-Doped SnS2 Monolayers for Lung Cancer Biomarkers (C3H6O, C6H6, and C5H8) Detection: A Density Functional Theory Investigation

“…21−23 Meanwhile, zeolite layers are capable of catalyzing the sensing performance of MOS upon C 3 H 6 O, C 6 H 6 , and C 5 H 8 gases. 22 In recent years, 2D materials have attracted much attention for lung cancer biomarker capturing due to their extremely high surface area−volume ratio, high sensitivity, rapid response, and the smaller size and other characteristics that could not be identified from other nanomaterials. 17,19 In 2010, Andre Geim and Konstantin Novoselov were granted the Nobel Prize in Physics for their discovery of the carbon monolayer known as graphene, 24 which sparked a new era in the development of gas sensors utilizing 2D monolayers.…”

“…Nevertheless, it is time consuming and expensive and requires proficient professionals, thus stimulating the need of biosensors for lung cancer biomarkers with rapid and effective detection. , Within the past few decades, there is an increasing interest in utilizing nanomaterials for C 3 H 6 O, C 6 H 6 , and C 5 H 8 sensing due to their naturally active surface, small size and cost-effectiveness . Carbon nanotubes (CNT) have shown high potential for sensing these three gases thanks to their large specific surface area, small tip ratios and high conductivity. , Besides, other nanomaterials such as metal–organic frameworks (MOFs) and metal oxide semiconductors (MOS) are also desirable for sensing the three molecules due to their tunability, low cost and small size. − Meanwhile, zeolite layers are capable of catalyzing the sensing performance of MOS upon C 3 H 6 O, C 6 H 6 , and C 5 H 8 gases . In recent years, 2D materials have attracted much attention for lung cancer biomarker capturing due to their extremely high surface area–volume ratio, high sensitivity, rapid response, and the smaller size and other characteristics that could not be identified from other nanomaterials. , …”

“… 21 − 23 Meanwhile, zeolite layers are capable of catalyzing the sensing performance of MOS upon C 3 H 6 O, C 6 H 6 , and C 5 H 8 gases. 22 In recent years, 2D materials have attracted much attention for lung cancer biomarker capturing due to their extremely high surface area–volume ratio, high sensitivity, rapid response, and the smaller size and other characteristics that could not be identified from other nanomaterials. 17 , 19 …”

Atomistic Descriptions of Gas-Surface Interactions on Tin Dioxide

“…Large scale deployment of such devices could, for example, screen for diabetes or detect imminent electric transformer failure by detecting gases characteristic to the processes [3,4]. However, despite their many advantages, CGS often suffer from cross-sensitivity to interfering gases and performance deterioration over time [5,6], and the main driving force in CGS research targets improvements in sensors' sensitivity, selectivity and response time. Insufficient understanding of the mechanisms of surface reactions makes improvements possible only through empirical exploration.…”