Disclosing the Sensitivity and Selectivity of Metal Oxide/Graphene Oxide-based Chemoresistors Towards VOCs

Nowadays, gas sensors play a vital role in a plethora of applications. However, there are still some important shortcomings, such as the scarce selectivity and sensitivity, especially at low operating temperatures. Herein, we report the successful sensing achieved by tailoring the chemoresistive materials comprised of graphene oxide (GO) sheets well-integrated in a three-dimensional network of n-type metal oxide semiconductors (MOS). Thanks to the synergistic effect between GO and MOS under UV light, we obtained a very good sensitivity (down to 100 ppb) towards different volatile organic compounds (VOCs, i.e., ethanol, acetone, ethylbenzene, toluene) even at room temperature. Moreover, the best performing sensor (SnO₂/GO 32:1) resulted highly selective towards polar compounds, such as acetone.