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

Abstract

ZnO/ZnFe2O4 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/ZnFe2O4 hollow nanocages by thermal annealing in air. The ZnO/ZnFe2O4 architecture is constructed by hollow nanocages with the scale around 100nm. To demonstrate its functional properties, the as-prepared products are utilized as sensing material for gas sensor. Significantly, the ZnO/ZnFe2O4 hollow nanocages exhibit enhanced response to acetone (25.8) with the detection limit of 1ppm at an optimum temperature of 290°C toward its two individual compositions (ZnO nanocages (7.9) and ZnFe2O4 nanospheres (8.1)). Moreover, the response of the ZnO/ZnFe2O4 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/ZnFe2O4 nanocages can be attributed to the unique porous and hollow structure, heterojunction and high response/surface area ratio.