Highly efficient ethanol sensor based on controllable synthesized ZnO hollow flower spheres

ZnO hollow flower spheres were successfully prepared by the low-cost and easy-to-operate solvent thermal method in combination with heat treatment. Characterization of the samples are finished via XRD, SEM, TEM, FIB and BET. It can be found that the growth time can largely affect the structure of the ZnO hollow flower spheres. The ZnO hollow flower spheres are regularly stacked by ultra-thin and porous nanosheets. And the size of spheres increases along with the growth time. The sensing properties of ZnO hollow flower spheres with different growth time were investigated. It can be found that the ZnO hollow flower spheres with the growth time of 4 h exhibit superior sensing performance in ethanol detection at the optimal operating temperature of 315 ℃. And, the ZnO hollow flower spheres have a good linear response to ethanol in concentration range of 1–100 ppm. The ZnO hollow flower spheres based gas sensor also has good selectivity and reliable stability. The good sensing performance of the ZnO hollow flower spheres can be attributed to the hollow structure, which brings larger surface area and large number of active sites. It is believed that the ZnO hollow flower spheres have great potential in practical application. [Display omitted] •The growth reaction time was controlled by solvothermal method to regulate the morphology of the samples.•The ZnO hollow flower spheres were successfully prepared.•The response of the hollow flower spheres toward 100 ppm ethanol reaches 35.•The ZnO-4 h hollow flower spheres sensor exhibits good selectivity against other toxic gases.•Hollow structure and fluffy surface contribute to good sensing properties.