Superior sensitivity and low detection limit of NO2 sensor based on layered tungsten oxide

In this study, well-designed layer-like WO 3 was synthesized by a facile hydrothermal route. Different characterization techniques have been conducted to comprehensively investigate the properties of morphology and structure of WO 3 -based sensing materials. The resultant consequences demonstrated that the layer-like WO 3 with abundant mesoporous structure displayed higher specific surface area with respect to the pristine WO 3 nanoplates. For the first time, the excellent gas sensing device based on layer-like WO 3 was constructed successfully, which achieved an admirable gas-sensing response of 106 towards 5 ppm nitrogen dioxide gas at the working temperature of 160 ℃, with a favorable selectivity, and the lowest detection limit was reached to 0.243 ppb. Moreover, the layer-like WO 3 sensor possessed considerable reproducibility and stability even in aging tests for 30 days. Those results can be ascribed to this promising structure optimization, which not only provides more reaction active sites but also promoted the gas sensing reaction procedure. Undoubtedly, this work is believed to be useful to offer a feasible strategy to enhance NO 2 gas response in practical application. • Lasagna-like WO 3 was first prepared by a facile hydrothermal reaction. • The gas sensor based on lamellar structure WO 3 showed excellent sensitivity towards NO 2 gas. • The lasagna-like WO 3 sensor can be utilized to detect ppb-level NO 2 .