Enhanced ethanol sensing performances of hetero-assembly Zn1-xFexO/rGO nanocomposites

Abstract

Nanocomposites of Zn1-xFexO/reduced graphene oxide (Zn1-xFexO/rGO, x = 0∼0.15) with carpet-like mesoporous structures have been simply synthesized via a low temperature hydrothermal method. FESEM and TEM results show that the hetero-assembly trend of Zn1-xFexO and rGO is much more striking than that of Zn1-xFexO self-assembly at 100 °C hydrothermal condition. The specific surface area and pore size tests indicate that rGO leads to the formation of slit holes with inclined panel structure, providing a large specific surface area for the nanocomposites. Mesoporous Zn0.89Fe0.11O has been proved to have the optimal gas response to ethanol at high operating temperatures, while Zn0.89Fe0.11O/rGO-10 (the content of rGO is 10 %) composite has a remarkable gas response (4.37) at low operating temperature and low ethanol concentration (160 °C, 2 ppm). In addition, the charge transport process and potential mechanism of gas response enhancement of Zn1-xFexO/rGO composite have been discussed in detail, and this may be ascribed to the combined effect of P-N junctions and the interfacial coupling between Zn1-xFexO and rGO.