Graphene-tungsten oxide nanocomposites with highly enhanced gas-sensing performance

Nanocomposites constructed by combining graphene (G) with oxide semiconductors have gained tremendous recent attentions in the field of gas sensors. In this work, we present a facile, green, and low-cost solvothermal process to synthesize the G-W18O49 nanocomposites with different G contents. The gas-sensing properties of the G-W18O49 nanocomposites towards ethanol and acetone vapors were systematically studied. Results showed that the amount of G had obvious influence on both the morphologies and the gas-sensing behaviors of the G-W18O49 nanocomposites. With low amount of 0.5 wt% G, the G-W18O49 nanocomposites exhibited significantly enhanced gas-sensing properties compared to pure W18O49 nanorods, which can be attributed to high yield and uniform distribution of the W18O49 nanorods decorated on the G surfaces as well as the synergistic effects between the G and W18O49 nanorods. The G-W18O49 nanocomposites are more sensitive to acetone than to ethanol, making them promising candidates for novel acetone sensors. This work shed light on the relationship between the G content and the gas-sensing performance of the G-W18O49 nanocomposites and could be extended to the development of other hybrid materials for gas-sensing applications.