Enhanced selective acetone-sensing performance of hierarchical hollow SnO2/α-Fe2O3 microcubes

Template controlled syntheses via metal-organic frameworks (MOFs) have emerged as a general strategy to fabricate metal oxides with tailoring porous structures. Here, novel hierarchical SnO2/α-Fe2O3 hollow microcubes have been obtained by post-loading of Sn2+ ions on the surface of Fe4(Fe(CN)6)3 microcubes and a followed thermolysis route. The as-formed hierarchical SnO2/α-Fe2O3 composites exhibit remarkable selective acetone sensing properties, in which the optimum composition shows the best responsibility toward acetone gas (with gas response Ra/Rg = 9.3 under the operating temperature of 270 °C), fast response/recovery speed (6 s/7 s to 200 ppm acetone at 270 °C), as well as excellent reproducibility. The applied strategy provides a general and controllable way to get access to other hierarchically structural multi-metal oxide architectures with intriguing morphologies and adjustable sensing properties.