Fabrication of ultra-sensitive NO sensor based on vacuum selenized WSe2nanorods

Abstract

Nitric oxide (NO) is one of the hazardous gases in air pollution, which is associated with surface ozone pollution and acid rain and affects vital human organs. Even a lower NO concentration is crucial to diagnose and track for environmental monitoring, air quality assurance, industries, and automotive machinery. Therefore, the fabrication of very sensitive and portable NO detectors that can detect the gas at relatively low concentrations (ppb level) is crucial for diagnosing and tracking the gas. To address these challenges, we have developed a WSe2 nanorods-based ultra-sensitive gas sensor that can detect small concentrations of NO (100 ppb) in a short period. WSe2 nanorods were grown by DC magnetron sputtering followed by vacuum selenization. The performance of the fabricated gas sensor was accessed over a broad range (100 ppb–20 ppm) of NO concentration at an optimized temperature of 250 °C. The fabricated sensor displays a relative sensor response of 38.98% at 100 ppb, which increases to 88.89% at 20 ppm. The analysis revealed that the grown WSe2 nanorods are sensitive enough to detect NO at very low concertation with a calculated detection limit of 24 ppb. The NO sensor exhibits high selectivity and stability with fast response/recovery time. The large surface area of grown WSe2 nanorods led to a better charge transfer process, resulting in excellent NO detection. The device revealed potential in environmental monitoring and biomedical applications along with prospects in wearable devices for real-time NO tracking.