Fabrication of ZnO/ZnFe2O4 hollow nanocages through metal organic frameworks route with enhanced gas sensing properties

ZnO/ZnFe 2 O 4 hollow nanocages have been designed and synthesized through a metal organic frameworks route, which involves two steps including the synthesis of Fe(III)MOF-5 nanostructured cages precursors and the subsequent transformation to ZnO/ZnFe 2 O 4 hollow nanocages by thermal annealing in air. The ZnO/ZnFe 2 O 4 architecture is constructed by hollow nanocages with the scale around 100   nm. To demonstrate its functional properties, the as-prepared products are utilized as sensing material for gas sensor. Significantly, the ZnO/ZnFe 2 O 4 hollow nanocages exhibit enhanced response to acetone (25.8) with the detection limit of 1   ppm at an optimum temperature of 290   °C toward its two individual compositions (ZnO nanocages (7.9) and ZnFe 2 O 4 nanospheres (8.1)). Moreover, the response of the ZnO/ZnFe 2 O 4 nanocages is even larger than that of other architectures, which follows the order hollow nanocages   >   double shell   >   hollow microsphere   >   hybrid hollow sphere   >   nanoparticle with rod. The remarkable gas sensing performance enhancement of ZnO/ZnFe 2 O 4 nanocages can be attributed to the unique porous and hollow structure, heterojunction and high response/surface area ratio.