Issue 46, 2018

Molybdenum carbide chemical sensors with ultrahigh signal-to-noise ratios and ambient stability

Abstract

Herein, we present a demonstration of the usability of the chemical sensing properties of transition metal carbides (TMCs) as gas sensing channels. Two phases of nanostructured molybdenum carbide (α-MoC1−x and β-Mo2C) with high porosities were perfectly synthesized by a temperature-programmed reduction (TPR) method, and they showed distinct metallic characteristics due to different density of states (DOS) localization status. The molybdenum carbide sensors showed novel gas sensing characteristics which have not been shown by previous typical sensing materials: predominantly, an unprecedentedly high signal-to-noise ratio (SNR) with the ability to detect the ppb levels of NH3 and NO2 was achieved, which is attributed to a combination of high electrical conductivity and superior catalytic properties. In addition to high sensitivity, unlike previous channel materials, the molybdenum carbide sensors showed very high ambient stability. The electrical conductivity and sensing performance are well preserved for half-year ambient exposure without any oxidation or degradation of channel materials, due to the good corrosion resistance and low chemical reactivity of molybdenum carbides. In addition, a versatile gas sensing response is observed according to the crystal phase of molybdenum carbides due to the distinct DOS of α-MoC1−x and β-Mo2C. We believe that this observation of new chemical sensing materials can shed light on the superior potential of TMCs for highly sensitive and stable low-power operating internet-of-things (IoT) sensors. In addition, owing to their ultra-high chemical stability and high melting temperature, TMCs can be utilized as channel materials for sensors in harsh operating conditions.

Graphical abstract: Molybdenum carbide chemical sensors with ultrahigh signal-to-noise ratios and ambient stability

Supplementary files

Article information

Article type
Paper
Submitted
25 iyl 2018
Accepted
19 okt 2018
First published
22 okt 2018

J. Mater. Chem. A, 2018,6, 23408-23416

Molybdenum carbide chemical sensors with ultrahigh signal-to-noise ratios and ambient stability

S. Cho, J. Y. Kim, O. Kwon, J. Kim and H. Jung, J. Mater. Chem. A, 2018, 6, 23408 DOI: 10.1039/C8TA07168C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements