Porous ZIF-8 Thin Layer Coating on ZnO Hollow Nanofibers for Enhanced Acetone Sensing

Metal oxide semiconductors have been extensively studied in detecting volatile organic compounds due to their low cost, good operability and ease of fabrication. However, sensitivity and selectivity are still huge challenges for commercial metal oxide semiconductor based gas sensor. Herein, nanostructured ZnO hollow fiber coated with porous zeolitic imidazolate framework-8 (ZIF-8) thin layers was developed as a new sensing platform to improve the performance of semiconductor-based gas sensor. It is shown that the resulting ZnO@ZIF-8 hollow nanofiber exhibited significant improvement of acetone sensitivity and selectivity as well as good long-term stability, owing to the high sensitivity of nanostructured ZnO hollow fibers and the good selectivity of porous ZIF-8 thin layers. Furthermore, the orientation growth of ZIF-8 layer on ZnO nanofibers also affected the gas sensing response to acetone. Thus, this study presents a novel way of building semiconductor@metal-organic frameworks hollow nanostructures to enhance gas response and selectivity of semiconductor-based gas sensors, and exhibits great potential in fabricating new generation gas sensors.