Hollow and hollowed-out Co3O4 nanoboxes (denoted as Co3O4-HHNBs) that assembled by porous ultrathin nanosheets (similar to 2 nm) have been synthesized through a morphology-conserved transformations of metal-organic framework (MOF) based precursors strategy and then applied to gas sensors. The switching process used a facile two-step approach, including the formation of box-shaped Co(OH)(2) followed by thermal conversion to Co3O4-HHNBs. The sensors based on Co3O4-HHNBs exhibit high response with the value of 56.6 to 100 ppm of toluene at 200 degrees C and 15.9 for ethanol at 220 degrees C, resp...
