Synthesis of ZnO hollow spheres through a bacterial template method and their gas sensing properties

In this report, ZnO hollow spheres were synthesized by an economic and environment-friendly bacterial template method. The hollow spheres resembled the morphology of the bacterial templates with multilayered porous shells. Their sensing properties were investigated with Co3O4 incorporation. The response of the spheres was enhanced from 8–11 to 38–49 to 100 ppm acetone with Co3O4 incorporation, and the response and recovery time were shortened from 10–12 s and 61–79 s to 1.2–1.9 s and 27–48 s, respectively.