Fe2O3 nanomaterials derived from Prussian blue with excellent H2S sensing properties

Abstract

Increasing demands for detection of toxic gases have attracted more and more attention to design and fabricate gas sensors with properties of ppb-level detectable, good selectivity, and long-term stability. In this paper, Prussian blue (PB) was utilized as precursor for preparation of Fe2O3. The morphology of PB was well tuned by different surfactants and synthesis temperatures, and following with calcination at 550 °C transformed them into Fe2O3 without changing the primary morphologies. The gas sensing properties of these as-prepared Fe2O3 materials were systematically tested. At the optimum operation temperature (200 °C), the sensors based on Fe2O3 nanocubes, nanospheres, and nanoflowers can detect H2S at ppb-level with low cross-sensitivity and excellent long-term stability. Experimental results reveal that the nanospheres based sensor have the best sensing performance, which follows the order nanospheres >nanocubes >nanoflowers. The results demonstrate that it is effective to improve the properties of metal oxide based gas sensor through morphology control by metal organic frameworks (MOFs)-templated route.