CH3SH and H2S Sensing Properties of V2O5/WO3/TiO2 Gas Sensor

Takafumi Akamatsu,Toshio Itoh,Yoshitake Masuda,Akihiro Tsuruta

doi:10.3390/chemosensors9050113

Takafumi Akamatsu, Toshio Itoh + Show 2 more

Open Access

https://doi.org/10.3390/chemosensors9050113

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Abstract

Resistive-type semiconductor-based gas sensors were fabricated for the detection of methyl mercaptan and hydrogen sulfide. To fabricate these sensors, V2O5/WO3/TiO2 (VWT) particles were deposited on interdigitated Pt electrodes. The vanadium oxide content of the utilized VWT was 1.5, 3, or 10 wt.%. The structural properties of the VWT particles were investigated by X-ray diffraction and scanning electron microscopy analyses. The resistance of the VWT gas sensor decreased with increasing methyl mercaptan and hydrogen sulfide gas concentrations in the range of 50 to 500 ppb. The VWT gas sensor with 3 wt.% vanadium oxide showed high methyl mercaptan and hydrogen sulfide responses and good gas selectivity against hydrogen at 300 °C.

Highlights

Human breath contains small amounts of biomarker gases, such as hydrogen (H2 ), nitric oxide (NO), carbon monoxide (CO), methane (CH4 ), and various volatile organic components, at low concentrations ranging from several parts per billion to parts per million [1,2,3,4]
The organoleptic intensity of oral malodor correlates with the levels of methyl mercaptan (CH3 SH) and hydrogen sulfide (H2 S), which are volatile sulfur compounds, in human breath [4]
Since the peaks assigned to TiO2, WO3, and V2 O5 were observed, no structural changes due to the formation of the complex oxide of V-W-Ti-O were observed

Summary

Introduction

Human breath contains small amounts of biomarker gases, such as hydrogen (H2 ), nitric oxide (NO), carbon monoxide (CO), methane (CH4 ), and various volatile organic components, at low concentrations ranging from several parts per billion (ppb) to parts per million (ppm) [1,2,3,4]. Semiconductor-based gas sensors are effective for respiratory gas analysis from the standpoints of cost, compactness, and power consumption [6,7,8,9,10,11]. Su et al reported that for NO2 sensing, a wearable, alveolus-inspired active membrane sensor based on the WO3 system showed excellent selectivity and thermal and humidity stability [6].

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