Fluorinated TiO 2 Hollow Spheres for Detecting Formaldehyde under UV Irradiation.
- Resource Type
- Article
- Authors
- Zhang, Jianwei; Huang, Baoyu; Li, Xinlei; Yang, Chao; Zhao, Wenzhuo; Xie, Xiuhua; Wang, Nan; Li, Xiaogan
- Source
- Materials (1996-1944). Feb2024, Vol. 17 Issue 4, p904. 17p.
- Subject
- *TITANIUM dioxide
*IRRADIATION
*SPHERES
*SURFACE reactions
*GAS detectors
*CHEMICAL reactions
*FORMALDEHYDE
- Language
- ISSN
- 1996-1944
The fluorinated titanium dioxide (F-TiO2) hollow spheres with varying F to Ti molar ratios were prepared by a simple one-step hydrothermal method followed by thermal processing. The diameter of the F-TiO2-0.3 hollow spheres with a nominal ratio of F:Ti = 0.3:1 was about 200–400 nm. Compared with the sensor based on pristine TiO2 sensing materials, the F-TiO2-0.3 sensor displayed an enhanced sensing performance toward gaseous formaldehyde (HCHO) vapor at room temperature under ultraviolet (UV) light irradiation. The F-TiO2-0.3 sensor demonstrated an approximately 18-fold enhanced response (1.56) compared to the pristine TiO2 sensor (0.085). The response and recovery times of the F-TiO2-0.3 sensor to 10 ppm HCHO were about 56 s and 64 s, respectively, and a limit-of-detection value of 0.5 ppm HCHO was estimated. The F-TiO2-0.3 sensor also demonstrated good repeatability and selectivity to HCHO gas under UV light irradiation. The outstanding HCHO gas-sensing properties of the F-TiO2-0.3 sensor were related to the following factors: the excitation effect caused by the UV light facilitated surface chemical reactions with analyte gas species; the hollow sphere structure provided sufficient active sites; and the surface fluoride (≡Ti−F) created additional chemisorption sites on the surface of the TiO2 material. [ABSTRACT FROM AUTHOR]