UV enhanced NO2 gas sensing at room temperature based on coral-like tin diselenide/MOFs-derived nanoflower-like tin dioxide heteronanostructures

• Published in: Sensors and actuators. B, Chemical Vol. 355; p. 131049
• Main Authors: Li, Tingting, Zhang, Dongzhi, Pan, Qiannan, Tang, Mingcong, Yu, Sujing
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.03.2022; Elsevier Science Ltd
• Subjects: Gas sensors; Heterostructure; Heterostructures; Hydrothermal; Metal-organic frameworks; Nanocomposites; Nanomaterials; Nitrogen dioxide; NO2 sensor; Photoelectrons; Room temperature; Selectivity; Sensors; Tin dioxide; Tin selenide; Ultraviolet radiation; UV illumination; Tin selenide; Heterostructure; NO2 sensor; Hydrothermal; Metal-organic frameworks; UV illumination
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2021.131049

In this paper, a coral-like tin diselenide/MOFs-derived flower-like tin dioxide (SnSe2/SnO2) nanocomposite film sensor was fabricated by hydrothermal method for NO2 gas detection. Many characterization methods were used to examine the structural composition and micro-morphology of SnSe2, SnO2, and SnSe2/SnO2 samples. At room temperature, the SnSe2/SnO2 composite film sensor had a higher response to 20 ppm NO2 gas when the mass ratio of SnSe2 and SnO2 was 1:2. A series of experiments were performed to investigate the NO2 sensing properties of this sensor. The results of gas-sensing tests indicated that the SnSe2/SnO2 (1:2) nanocomposite sensor had excellent NO2 gas sensitivity performance, better linearity and selectivity compared with pristine SnSe2 and SnO2 film sensors. In particular, the response value of the SnSe2/SnO2 nanocomposite sensor towards 20 ppm NO2 gas was obviously improved from 7.4 to 12.6 under UV illumination, and the response/recovery times towards 10 ppm NO2 gas were shortened from 110 s/160 to 80 s/144 s. The possible NO2 sensing mechanism was related to the heterostructure between n-type SnSe2 and n-type SnO2 nanomaterials, and at the same time, we proposed that photoelectrons excited by UV light could improve the sensing characteristics of the SnSe2/SnO2 nanocomposite towards NO2 gas. •The coral-like SnSe2/MOFs-derived nanoflower-like SnO2 heteronanostructures were fabricated by hydrothermal method.•The SnSe2/SnO2 nanocomposite sensor exhibited excellent NO2 sensing performance at room temperature.•The sensing properties of the SnSe2/SnO2 nanocomposite sensor were significantly improved under UV illumination.•The enhanced NO2 sensing performance was attributed to the formation of n-n heterostructure and light-excited electrons.