Atomic layer deposition of ZnO onto Fe2O3 nanoplates for enhanced H2S sensing

We report a gas sensor for testing H2S gas based on Fe2O3/ZnO heterostructure, which was synthesized using the atomic layer deposition (ALD) technique. Compared with the Fe2O3 nanosheet gas sensor and ZnO gas sensor, the Fe2O3/ZnO heterostructure gas sensors exhibits better sensing performance at the temperature ranging from 150 °C to 350 °C. In the environment of 100 ppm H2S at 250 °C, the highest response of Fe2O3/ZnO heterostructure gas sensor, about 133.1, was obtained, which is approximately 15-fold as large as that of the Fe2O3 nanosheet gas sensor (about 8.7). In addition, the response of Fe2O3/ZnO heterostructure gas sensor reached 21.7, 11.3, 4.9, 6.7, 3.6-100 ppm isopropanol, NO, acetone, ethanol, and methane in the same condition, respectively. These results also reveal that the Fe2O3/ZnO heterostructure gas sensor exhibited the high selectivity. Our results suggest that the Fe2O3/ZnO heterostructure can be a promising candidate for high-performance H2S gas sensors.