Room Temperature Methanol Sensors Based on Rod-Shaped Nanostructures of MoS2 Functionalized With Ag Nanoparticles

Abstract

In this work, molybdenum sulfide (MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) nanostructures were prepared by a hydrothermal method to detect methanol vapor. The effect of adding different amounts of Ag nanoparticles (0.5wt%, 1wt%, 2wt%, 2.5wt%, and 5wt%) to MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> on the response of sensors was investigated. All sensors could suitably detect methanol at room temperature. The response of sensors based on pure MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Ag (2wt%) to 100 ppm of methanol was 7.1% (lowest response) and 21.6% (highest response), respectively. It was found that adding Ag nanoparticles greatly increases both sensitivity and selectivity. The structural, morphological, and composition properties of the prepared materials were approved by XRD, SEM, TEM, and EDX techniques. As another advantage, the proposed sensors can be easily recovered in the air at room temperature without the need for additional energy. By exposing the sensors to three successive cycles of methanol/air as well as testing them within 6 weeks, it was found that the sensors have good repeatability and chemical stability. By examining the response to different analytes, it was found that the sensors can selectively detect methanol with high sensitivity. Therefore, our low-cost (PCB-based) sensors are suitable options for the preferable detection of methanol in different industries.