Hierarchically Assembled Zno Nanorods On Tio2 Nanobelts For High Performance Gas Sensor

Gas sensors based on semiconductors have wide applications. In this study, TiO2 nanobelts prepared from alkali-hydrothermal process were used to hierarchically assemble ZnO nanorods to form a surface heterostructure. The as-synthesized hierarchical heterostructure was confirmed with characterizations. The possible grown mechanism was investigated. The hierarchical heterostructure was used to assemble gas sensor. The sensing performance of the assembled gas sensor was explored using different gas, and it is found that the hierarchical heterostructure sensor has excellent sensitivity and selectivity upon exposure to trimethylamine gas. The sensitivity was about 25 at the concentration as low as 5 ppm of trimethylamine. The best working temperature was determined to be 200 degrees C. The sensing mechanism was also discussed and proposed to be related to a surface-depletion model.