A Sensitive Benzene Gas Sensor Utilizing Thermal Desorption Coupled with Cataluminescence

A new method based on cataluminescence (CTL) generated on the surface of nanosized Bi₂O₃ was proposed for direct determination of benzene in air. Trace benzene was firstly absorbed on active carbon at room temperature to concentrate, then desorbed at 130°C to inject. The method showed high selectivity to benzene at wavelength of 440 nm, satisfying activity at reaction temperature of 315°C and good stability at air carrier flow rate of 135 ml/min. The linear range of CTL intensity versus concentration of benzene was 0.3~75 mg/m³ (γ=0.9991), and the detection limit (3σ) was 0.1 mg/m³. The recovery of testing benzene in 5 artificial air samples by this method was 96.9%-105.0%. This method allowed rapid determination of benzene in air.