A comparative study on simple and practical chemical gas sensors from chemically modified graphene films

The large specific surface area and strong adsorption ability of graphene oxide and its derivates such as partially or fully reduced graphene oxide are attractive for gas-sensing applications. Such materials are also easy to work with and are economically attractive and are thus suited to large scale fabrication. Here we compare graphene oxide with two partially reduced graphene oxide materials. In the first, ascorbic acid is used as a weak reducer and in the second, we demonstrate a new thiolation/reduction route which can also partially reduce graphene oxide and in addition provide thiol groups at the surface. We then compare the three materials for use in a simple drop-cast sensor system. The signal profile data from the three different sensors vary in shape and intensity as well as response and recovery times for the two different analytes investigated. The data suggests these parameters could be used as an array system to discriminate between analytes.