Functionalization of Graphene and Its Derivatives for Developing Efficient Solid-State Gas Sensors: Trends and Challenges

Abstract

In the recent past, graphene and its potential derivatives (like graphene oxide (GO) and reduced graphene oxide (rGO)), owing to their unprecedentedly advantageous physicochemical properties, grabbed the limelight of the gas sensor research arena. However, in spite of the strikingly impressive properties of pristine graphene, this can seldom be employed as the gas sensing material, particularly for detecting reducing species due to extremely low resistance and agglomeration tendency among the layers of pristine graphene. To mitigate this problem, the researchers across the globe explored graphene oxide and reduced graphene oxide and succeeded partially. However, for the last couple of years, another alternative was intensively investigated by the researchers where the surface/edge of the graphene (or its derivatives) is functionalized through modification by metal, metal oxide nanoparticles, or polymer (these functionalizing elements are introduced either individually or combinedly). Till date, researchers have improvised numbers of covalent and non-covalent routes to functionalize the graphene with desirable surface properties, suitable for developing efficient solid-state gas sensor devices. Such functionalization of graphene surface plays favorable role for the adsorption–desorption of a particular target gas on the sensing surface (hence, enhanced sensitivity and/or selectivity) as well as tune the electrical property of graphene, favorable for fast and promising gas sensing performance. The present book chapter comprehensively summarizes the recent advancement and strategies on functionalization of graphene and its derivatives for the development of efficient gas sensor devices. Finally, concluding remarks are presented to discuss the challenges with focus on the future direction of research endeavors.