The sensing properties of SnO₂ based CO gas sensors can be affected by ambient humidity and oxygen pressure. In this study the effect of oxygen vacancy along with the adsorption mechanism of H₂O and CO on SnO₂ (110) surface has been investigated by performing density functional theory (DFT) calculations. The influence of ambient humidity has been taken into consideration in order to better understand the CO sensing mechanism in SnO₂ based gas sensors. Molecular and dissociative adsorption of H₂O on both stoichiometric and oxygen deficient surface were simulated. Adsorption energies, Bader charge analysis and the projected density of states were investigated by employing electronic structure calculations. The findings show that CO adsorption in most cases is less favorable in the presence of H₂O and on the reduced SnO₂ surface. However, oxygen vacancies provide more sites to adsorb H₂O molecules to compensate the humidity cross-interference. Furthermore, CO to CO₂ conversion along with dissociative H₂O adsorption on the vacancy of oxygen site presents the highest charge transfer and very strong adsorption energy among other adsorption configurations. These findings provide a guideline for fabricating more efficient CO sensors.

基于SnO ₂的CO气体传感器的传感特性会受到环境湿度和氧气压力的影响。在这项研究中，通过执行密度泛函理论（DFT）计算，研究了氧空位以及H ₂ O和CO在SnO ₂（110）表面上的吸附机理。为了更好地了解基于SnO ₂的气体传感器中的CO传感机制，已经考虑了环境湿度的影响。H _2的分子和解离吸附模拟了化学计量表面和缺氧表面上的O。通过采用电子结构计算，研究了吸附能，巴德电荷分析和预计的态密度。该发现表明，在大多数情况下，在H ₂ O存在下和还原的SnO ₂表面上，CO吸附效果较差。但是，氧空位提供了更多的位置来吸附H ₂ O分子以补偿湿度的交叉干扰。此外，CO到CO _2的转化以及离解H _2的转化在其他吸附构型中，氧空位上的O吸附呈现出最高的电荷转移和非常强的吸附能。这些发现为制造更高效的CO传感器提供了指导。