采用基于密度泛函理论的第一性原理平面波超软赝势方法计算了金红石TiO2(110)纯净表面以及掺杂N、掺杂Rh和N/Rh共掺表面吸附CO分子后的光学气敏传感特性。研究发现:纯净和掺杂表面吸附CO分子后均表现出光学气敏传感特性,其原因是表面氧空位的氧化作用;而N/Rh共掺杂对表面氧化性改善得最多,吸附CO分子后吸附距离最小,吸附能最大,稳定性最好,且易于实现。因此,相比于纯净及单掺杂体系,N/Rh共掺杂表面对气体有更好的光学气敏传感效应,是一种改进TiO2光学气敏传感材料的良好方式。

The first-principles plane-wave supersoft pseudopotential method based on the density functional theory (DFT-D) is used to determine the optical CO gas-sensing properties of pure, single-doped N, single-doped Rh, and N/Rh codoped rutile TiO₂ (110) surfaces. We observe that the pure and doped surfaces of rutile TiO₂ exhibit certain optical CO gas-sensing characteristics that results from variations in surface oxidation performance. We find that N/Rh codoping greatly improves surface oxidation. The adsorption of CO gas on an N/Rh co-doped surface is characterized by a negligent adsorption distance, enormous adsorption energy, and unparalleled stability after adsorption; it is also easy to implement. Therefore, N/Rh co-doped surfaces are more effective at optical gas sensing when compared with pure and single-doped surfaces, and N/Rh codoping is a suitable way to improve the optical gas-sensing properties of TiO₂.