Low-Temperature and High-Sensing Chlorine Sensor Based on Mesoporous SnO<sub>2</sub> Wrinkled Nanosheets Inherited from Waste Cabbage Leaves
Bao-Yu Song, Ming Yang, Zhao-Qi Cui, Rui Gao, Xian‐Fa Zhang, Zhao‐Peng Deng, Yingming Xu, Li-Hua Huo, Shan Gao
Abstract
How to construct a metal oxide-based chlorine sensor with low temperature and high sensing remains challenging due to the very less report. Herein, discarded cabbage leaves biotemplate was simply soaked into SnCl 4 solution, and the obtained precursors were calcined at 650 °C to generate SnO 2 wrinkled nanosheets (SnO 2 -650). Its multistage structure is assembled from small-size and well-crystallized nanoparticles, which are covered by a layer of nanospherical aggregates. Meanwhile, it also has uniform mesopore distribution, large specific surface area, and rich oxygen vacancies. Therefore, the synergism of these favorable factors results in excellent overall sensing performances toward trace Cl 2 . At near room temperature, the SnO 2 -650 sensor exhibits a ultrahigh response value of 2460 for 10 ppm of Cl 2, representing the second highest value for currently reported metal oxide-based sensors. In comparison, at 92 °C, this sensor can rapidly restore to the initial resistance value, and its response value can reach up to 611 to the same concentration of Cl 2, which is 11.8 and 13.3 times higher than those of SnO 2 -TF ( S = 52) and SnO 2 -750 ( S = 46) sensors. Also, it possesses high selectivity, low practical detection limit, good repeatability, and stability. In addition, its enhanced sensing mechanism is discussed in detail.