Highly Sensitive and Selective Hydrogen Gas Sensor Using the Mesoporous SnO₂ Modified Layers.

Niuzi Xue,Shunping Zhang,Pan Zong,Feng Yang,Qinyi Zhang

doi:10.3390/s17102351

Abstract

It is important to improve the sensitivities and selectivities of metal oxide semiconductor (MOS) gas sensors when they are used to monitor the state of hydrogen in aerospace industry and electronic field. In this paper, the ordered mesoporous SnO2 (m-SnO2) powders were prepared by sol-gel method, and the morphology and structure were characterized by X-ray diffraction analysis (XRD), transmission electron microscope (TEM) and Brunauer–Emmett–Teller (BET). The gas sensors were fabricated using m-SnO2 as the modified layers on the surface of commercial SnO2 (c-SnO2) by screen printing technology, and tested for gas sensing towards ethanol, benzene and hydrogen with operating temperatures ranging from 200 °C to 400 °C. Higher sensitivity was achieved by using the modified m-SnO2 layers on the c-SnO2 gas sensor, and it was found that the S(c/m2) sensor exhibited the highest response (Ra/Rg = 22.2) to 1000 ppm hydrogen at 400 °C. In this paper, the mechanism of the sensitivity and selectivity improvement of the gas sensors is also discussed.

Highlights

As one of the most important clean energies, H2 is widely used in various fields such as fuel cell vehicles, aerospace industry, petrochemical industry, and electronic field [1,2,3]
The present study aims to develop a low cost and highly sensitive and selective hydrogen gas sensor
SnO2sensors sensorshave have been compared with results reported byother the Experimental results been compared with the the results reported by the other researchers on sensors

Summary

Introduction

As one of the most important clean energies, H2 is widely used in various fields such as fuel cell vehicles, aerospace industry, petrochemical industry, and electronic field [1,2,3]. In consideration of the leakage in the applications of H2 whose explosive limit is very low, it is essential to monitor the state of hydrogen. Gas sensor is one of the most effective detectors [4,5]. Great emphasis is being given to metal oxide semiconductors (MOS), including ZnO [6], WO3 [7], TiO2 [8], In2 O3 [9] and SnO2 [10], as gas sensing materials for a long time. Among various MOS gas sensors, SnO2 -based gas sensors are widely used because of their low cost, high sensitivity and long-term stability [11]. Poor selectivity to various gases restricts their applications

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