Accumulated Chemical Adsorption Phenomenon of H2 on MOX Gas Sensor Under Temperature Programmed Cooling

摘要

For improving the sensitivity of MOX gas sensor, one of the effective methods is to increase the chemical adsorption of gas on the surface. This paper focused on the effect of temperature programmed cooling on the adsorption accumulation of the gas owning one chemical adsorption state. Herein, the experiments of resistance response test, work function test, and the theoretical simulation were conducted to investigate the chemical adsorption of H+ on MOX gas sensor. Compared with the constant temperature test, the resistance response and the work function change were both significantly increased for H2 detection in oxygen-free environment under temperature programmed cooling. Furthermore, the process of temperature programmed cooling was theoretically simulated based on the Langmuir adsorption model. The accumulated chemical adsorption phenomenon was revealed by the simulation. In brief, this discovery opens a way for the sensitivity improvement of MOX gas sensor.