Sensitivity enhanced microfiber interferometer ammonia gas sensor by using WO3 nanorods coatings

Rapid and accurate detection of toxic and harmful gases in the environment is an important means to prevent poisoning and leakage accidents. A tapered microfiber interferometer coated by WO₃ nanorods for gas sensing is fabricated by using flame melting biconical taper method. As a coated material for the microfiber interferometer (MFI) ammonia gas sensor, the WO₃ nanorods are made by hydrothermal method, and are dripped onto the surface of the sensor. The WO₃ nanorods coating on the sensor surface can absorb ammonia molecules and generate charge transfer, which results in the shift of transmission spectrum. The experimental results show that the prepared sensor has high sensitivity and selectivity to ammonia gas. When the ammonia gas concentration is from 0 to 11640 ppm, the spectrum shift of the WO₃ nanorods coated sensor is 16.23 nm. The sensor has good repeatability, selectivity and wide application prospects in the monitor of harmful gases.