Self-sacrificing templated formation of Co3O4/ZnCo2O4 composite hollow nanostructures for highly sensitive detecting acetone vapor

Hollow nanostructures derived from metal-organic frameworks have attracted considerable interest for prospective applications in gas separation/storage, drug delivery, catalysis device and gas sensors. Herein, porous hollow nanostructures, namely Co3O4/ZnCo2O4 composite hollow nanostructures, are prepared through a self-sacrificing template method. The method includes the synthesis of zeolite imidazolate frameworks-67 self-sacrificing template and then transformation into Co/Zn-ZIF@Co-Zn layered double hydroxides precursor. Finally, the Co3O4/ZnCo2O4 composite hollow nanostructures are obtained through thermal annealing of Co/Zn-ZIF@Co-Zn LDH precursor in air. The gas sensing investigations revealed that the Co3O4/ZnCo2O4 composite hollow nanostructures-based gas sensor exhibited high response (16.3-100 ppm) and selectivity towards acetone. Besides, enhanced gas sensing properties of Co3O4/ZnCo2O4 composite hollow nanostructures are observed when compared with Co3O4 and ZnCo2O4 hollow nanostructures. The excellent gas sensing characteristics of Co3O4/ZnCo2O4 composite hollow nanostructures might be attributed to their high porosity, large specific surface area, and heterostructure between Co3O4 and ZnCo2O4.