A novel and sensitive formaldehyde gas sensor utilizing thermal desorption coupled with cataluminescence

A highly sensitive gas sensor based on thermal desorption coupled with cataluminescence (TD/CTL) using TiO2-Y2O3 (mass ratio 1:3) as a probe was firstly proposed for the determination of formaldehyde in air. Quantitative analysis was performed at an optimal adsorbent of active carbon, thermal desorption temperature of 140 °C, catalytic temperature of 195 °C, a wavelength of 490 nm and a flow rate of 280 mL/min. The linear range of CTL intensity versus concentration of formaldehyde was 0.026–1.30 mg/m3 (r = 0.9990, n = 7), and the detection limit (3σ) was 0.01 mg/m3. There was no or weak response to foreign substances, such as benzene, ethanol, chloroform, carbon tetrachloride, toluene, dimethylbenzene and n-hexane. This proposed formaldehyde gas sensor showed the high sensitivity, rapid response, good stability, and allowed on-line monitoring of formaldehyde in air.