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

Co3O4/NiCo2O4 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 Co3O4/NiCo2O4 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 Co3O4/NiCo2O4 DSNCs. The use of as-prepared Co3O4/NiCo2O4 DSNCs as a gas sensing material in a gas sensor gave an enhanced sensitivity to acetone compared with result obtained in Co3O4 nanocages (NCs). In addition, excellent reversibility and selectivity of the sensor were observed. These properties make the Co3O4/NiCo2O4 DSNCs a good candidate for acetone detection.