Ethanol detection using composite based on reduced graphene oxide and CuO hierarchical structure under wet atmosphere

[Display omitted] •RGO-CuO composite was obtained by a one-pot microwave-assisted hydrothermal method.•RGO-CuO composite could be used for ethanol detection under high humid conditions.•The enhanced ethanol response can be attributed to the RGO/CuO interface. Semiconductor metal oxides have been used for detecting volatile organic compounds (VOCs). However, these materials present a poor performance in humidity. Here, we report the effect of reduced graphene oxide (RGO) on the ethanol-sensing of CuO under dry and in the relative humidity range of 36–90%. For this purpose, RGO-CuO composites and CuO were synthesized by a one-step microwave-assisted synthesis. The VOCs sensing were performed at the range of 150–350 °C to acetone, benzene, ethanol, methanol, and m-xylene. The RGO-CuO composites exhibited enhanced ethanol sensing when compared with pure CuO at the optimal operating temperature of 250 °C. In addition, the optimal RGO content resulted in an enhanced selectivity and high sensitivity compared to pure CuO. The enhanced ethanol sensing performance of RGO-CuO was attributed to the RGO/CuO heterojunction. Thus, the combination of RGO and p-type CuO semiconductor can be a promising for VOCs detection under wet conditions.