ZIF-67 MOF-derived unique double-shelled Co3O4/NiCo2O4 nanocages for superior Gas-sensing performances

Unique nanostructures of bimetallic organic materials assisted by new organic frameworks are promising candidates for gas sensor applications. For the first time, we successfully report the design and synthesis of Co3O4/NiCo2O4 double-shelled nanocages (DSNCs) via a facile template-assisted method. The DSNCs were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric (TG) analysis, and transmission electron microscopy (TEM). The nanocages had a high surface-to-volume ratio and a high surface area of 103 m(2) g(-1). The as-prepared nanostructures were exposed to various reducing gases at different controlled gas concentrations and working temperatures. The fabricated sensors exhibited high selectivity and gas-sensing responses toward H2S at an optimal temperature of 250 degrees C for 100 ppm. The outstanding gas-sensing performance revealed the potential application of the unique double-shelled hollow nanostructures to the gas sensor industry.