Heterojunction Bi₂O₃-TiO₂ Nanofiber as Cataluminescence Material for Detection of Toluene

Bi2O3-TiO2 nanofibers ( NEs ) were synthesized by electrospinning method, and a geterojunction cataluminescence toluene gas sensor was thus designed by depositing Bi2O3-TiO2 NFs onto the cylindrical ceramic heating rod surface as cataluminescence material by clip-coating method. The crystalline phase and microstructure of Bi2O3-TiO2 NFs were displayed using X-ray diffraction and scanning electron microscope , and the cataluminescence mechanism and electrochemical characteristic of Bi2O3-TiO(2 )NFs in detection of toluene were analyzed by UV-Vis spectrometry , X-ray photoelectron spectroscopy and Fourier infrared spectroscopy (FT-IR). Density functional theory (DFT) was used to calculate the charge density and differential charge density of atoms in Bi2O3-TiO2 NFs heterojunction, and the sensitization mechanism of sensor was further proposed for detecting toluene gas. Under the optimal conditions including 450 nm of wavelength, 200 mL/min of flow rate and at 250 degrees C , there was a good relationship between the CTL intensity of Bi30 toluene gas sensor and the toluene concentration in the range of 0. 1-200 mu g/m(3). The detection limit was 0. 1 mu g/m(3) (S/N= 10) , the RSD was 1. 81% , and the dynamic response time and recover time of toluene gas sensor were 7. 2 s and 9. 4 s respectively. This study provided a feasible strategy for rapid and efficient detection of toluene , as well as a new sensing platform for detection of volatile organic compounds.