A series of hexagonal-like alpha-Fe2O3/ZnO/Au nanoplate heterostructures with tunable morphologies and superior ethanol gas-sensing performance were successfully synthesized via the facile multi-step reaction processes. Hexagonal-like alpha-Fe2O3 nanoplates with uniform size around 150 nm are employed as new sensor substrates for loading the well-distributed ZnO and Au nanoparticles with adjustable size distribution on the different surfaces. Brunauer-EmmeQ-Teller (BET) surface areas of alpha-Fe2O3 and alpha-Fe2O3/ZnO samples are evaluated to be 37.94 and 61.27 m(2)/g, respectively, while alpha-Fe2O3/ZnO/Au composites present the highest value of 79.08 m(2)/g. These alpha-Fe2O3-based functional materials can exhibit outstanding sensing properties to ethanol. When the ethanol concentration is 100 ppm, the response value of alpha-Fe2O3/ZnO/Au composites can reach up to 170, which is 14.6 and 80.3 times higher than that of alpha-Fe2O3/ZnO and pure alpha-Fe2O3, respectively. The recycling stability and long-time effectiveness can be availably maintained within 30 days, as well as the response and recovery times are shortened to 4 and 5 s, respectively. Significantly, the response value of alpha-Fe2O3/ZnO/Au composite is still up to 63 at an operating temperature of 280 degrees C even though the ethanol concentration decreases to 10 ppm. The enhanced gas sensing mechanism would be focused on the synergistic effects of phase compositions, surface heterogeneous structures, large specific surface area, and the selective depositions of Au nanoparticles in alpha-Fe2O3/ZnO/Au sensors. The synergistic effect of different surface heterostructures referring to alpha-Fe2O3/Au and alpha-Fe2O3/ZnO/Au and their novel electron transport processes on the surfaces are first investigated and discussed in details. It is expected that hexagonal-like alpha-Fe2O3/ZnO/Au nanoplate heterostructures with excellent sensing performance can be the promising highly-sensitive materials in the actual application for monitoring and detecting ethanol. (C) 2018 Elsevier B.V. All rights reserved.