A bimodal distribution of the probability density function was used to construct the pore size distribution model,and the simulation results are validated by comparing with the experimental data. Taking the pore structure effects into account,a diffusion-reaction mathematical model has been established and solved to study the effect of pore size distribution on response time, sensitivity and selectivity of porous gas sensor. The results indicate that, pore structure with bimodal pore size distribution is of certain practical significance to the improvement of the response rate, sensitivity and selectivity of gas sensor. Diffusion resistance was opposite to the specific surface area as the pore structure changes, which have cooperative effect on the surface reaction rate of target gas. The relative sensitivity has a maximum value when the probability of subsequent peak increased from 0 tol. While the 80% response time of the porous gas sensor shortened gradually as the probability of subsequent peak increases.%采用一种可双峰分布的概率密度函数构建孔径分布模型,并与实验测量结果进行对比验证.建立了包含孔结构影响的气体扩散-反应数学模型,数值研究了多孔气体传感器内孔径分布形态对响应时间、灵敏度和选择性的影响规律.计算结果表明,双峰分布孔结构对提高传感器的气敏性能具有一定实际意义.孔结构变化时,孔内扩散阻力和比表面积呈相反变化趋势,共同影响传感器内被测气体的表面反应速率.多孔气体传感器对被测气体的80％响应时间随副峰概率的增大而逐渐缩短.多孔气体传感器的相对灵敏度则随副峰概率呈极值性变化,具有极大值.
展开▼
