Study on the Deterioration Mechanism of Pb on TiO₂ Oxygen Sensor

Previous studies have shown that the pollutants in exhaust gas can cause performance deterioration in air-fuel oxygen sensors. Although the content of Pb in fuel oil is as low as 5 mg/L, the effect of long-term Pb accumulation on TiO₂ oxygen sensors is still unclear. In this paper, the influence mechanism of Pb-containing additives in automobile exhaust gas on the response characteristics of TiO₂ oxygen sensors was simulated and studied by depositing Pb-containing pollutants on the surface of a TiO₂ sensitive film. It was found that the accumulation of Pb changed the surface gas adsorption state and reduced the activation energy of TiO₂, thus affecting the steady-state response voltage and response speed of the TiO₂-based oxygen sensor.