MOF-derived Co3O4/NiCo2O4 double-shelled nanocages with excellent gas sensing properties

Abstract Co 3 O 4 /NiCo 2 O 4 double-shelled nanocages (DSNCs) were successfully prepared through a metal-organic frameworks (MOFs) route. The strategy includes the synthesis of zeolite imidazolate framework-67 (ZIF-67)/Ni-Co layer doubled hydroxides precursor and subsequent transformation to Co 3 O 4 /NiCo 2 O 4 DSNCs by thermal annealing of the as-prepared precursor in air. Various techniques such as XRD, SEM/EDS, BET and TEM were employed for the characterization of microstructure and morphology of the as-prepared Co 3 O 4 /NiCo 2 O 4 DSNCs. The use of as-prepared Co 3 O 4 /NiCo 2 O 4 DSNCs as a gas sensing material in a gas sensor gave an enhanced sensitivity to acetone compared with result obtained in Co 3 O 4 nanocages (NCs). In addition, excellent reversibility and selectivity of the sensor were observed. These properties make the Co 3 O 4 /NiCo 2 O 4 DSNCs a good candidate for acetone detection.