Design of Cr2O3@ZnO Hetero-junction Hierarchical Nanostructures with Enhanced Xylene-sensing Properties

Cr2O3@ZnO hetero-junction hierarchical nanostructures were designed to be enhanced xylene sensing material, and thereinto, flower-like ZnO hierarchical nanostructures were synthesized via a solution-based method, and then Cr2O3 particles were developed on the surface of ZnO petals via a solvothermal method. From the results of XRD patterns, SEM and TEM images, it can be observed that ZnO has a high-quallity crystallinity and Cr2O3 particles scatter uniformly on the suruface of ZnO. The products with different ratios of Cr2O3 were used to fabricate gas sensors, and the result indicates that the hetero-junction structures prompt the response to xylene, and the reason may be attributed to the decrease of main carriers concentration caused by the p-n junction between ZnO(n-type semiconductor) and Cr2O3(p-type semiconductor), as well as the catalytic oxidation effect on methyl groups of the xylene by Cr2O3.