Formaldehyde Gas Sensor Based on MoS2/RGO 2D/2D Functional Nanocomposites

Abstract

Formaldehyde is the most common indoor air contaminant (exposure limit of 30 min for 0.08 ppm has been set by WHO, World Health Organization) emitted from common building materials including wood furniture, carpets, plastic products, paints, varnishes. It is recently classified as carcinogenic and is associated with many other health risk factors such as respiratory disorders, nervous system damage that prompted the interest of scientific community in developing compact, simple, fast, and efficient gaseous formaldehyde room temperature detection materials. In the present work, MoS2/RGO nanocomposites are developed as a hybridized 2D/2D functional nanocomposite chemiresistive sensing material for efficient formaldehyde detection. The MoS2/RGO as 2D/2D nanocomposite sensing material addresses the challenges faced by existing flexible unary 2D sensing material such as selectivity, sensitivity, stability, response, and recovery time. The MoS2/RGO nanocomposites are characterized through XRD and FTIR techniques. The electrical and sensing studies of synthesized material are evaluated through I–V characteristics using Keithley electrometer. Results revealed that the 2D/2D nanocomposites’ heterogeneous nature, high density of exposed active sites, heterojunction effect preventing charge accumulation during interaction with gas and catalytic properties of the individual constituents enhance the potential in terms of sensitivity, recovery, and response time of the sensing material.