Interdigitated electrodes-based Au-MoS2hybrid gas sensor for sensing toxic CO and NH3gases at room temperature

Saurabh Rawat; Priyanka Bamola; Chanchal Rani; Vishakha Kaushik; Ujjwal Kumar; Charu Dwivedi; Rekha Rattan; Mohit Sharma; Rajesh Kumar; Himani Sharma

doi:10.1088/1361-6528/acd0b7

Interdigitated electrodes-based Au-MoS₂hybrid gas sensor for sensing toxic CO and NH₃gases at room temperature

Nanotechnology. 2023 May 12;34(30). doi: 10.1088/1361-6528/acd0b7.

Authors

Affiliations

¹ Functional Nanomaterials Research Laboratory, Department of Physics, Doon University, Dehradun, Uttarakhand 248001, India.
² Materials and Device Laboratory, Department of Physics, Indian Institute of Technology Indore, Indore 453552, India.
³ Department of Physics, DIT University, Dehradun 248001, India.
⁴ School of Environment and Natural Resource, Doon University, Dehradun, Uttarakhand 248001, India.
⁵ Department of Chemistry, School of Physical Sciences, Doon University, Dehradun- 248001, India.
⁶ Department of Prosthodontics Saveetha Dental College and Hospitals, SIMATS, Chennai-60077, India.
⁷ Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 138634, Singapore.

PMID: 37105139
DOI: 10.1088/1361-6528/acd0b7

Abstract

In the quest to create effective sensors that operate at room temperature, consume less power and maintain their stability over time for detecting toxic gases in the environment, molybdenum disulfide (MoS₂) and MoS₂-based hybrids have emerged as potent materials. In this context, the current work describes the fabrication of Au-MoS₂hybrid gas sensor fabricated on gold interdigitated electrodes (GIEs) for sensing harmful CO and NH₃gases at room temperature. The GIEs-based Au-MoS₂hybrid sensors are fabricated by decorating MoS₂nanoflowers (MNF) with varying size of Au nanoparticles using an inert gas evaporation technique. It is observed that by varying the size of Au nanoparticles, the crystallinity gets modified, as confirmed by x-ray diffraction and Micro-Raman spectroscopy (μRS). The gas sensing measurements revealed that the best sensing response is found from the Au-MoS₂hybrid (with an average particle size of 10 nm). This particular hybrid shows a 79% response to CO exposure and a 69% response to NH₃exposure. The measurements are about 3.5 and 5 times higher than the bare MoS₂when exposed to CO and NH₃at room temperature, respectively. This enhancement in sensing response is attributed to the modified interfacial interaction between the Au nanoparticles and MNF gets improved, which leads to the formation of a Schottky barrier, as confirmed using x-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy analysis. This enables the development of efficient gas sensors that respond quickly to changes in the gas around them.

Keywords: 2D materials; MoS2; gas sensors for toxic gases; gold interdigitated electrodes; room temperature sensing; transition metal dichalcogenides (TMDs).