气体分子在Co-BN表面吸附的第一性原理研究

First principles study of gas molecules on Co-BN surface

采用包含色散力校正的密度泛函理论(DFT-D)方法系统地研究了气体分子(O_2,H_2,NO,CO,CO_2,SO_2,H_2S,H_2O)在Co掺杂单层BN(Co-BN)表面的吸附,分析了吸附小分子的几何结构,吸附能,电荷转移等情况.结果表明:1)CO等气体分子主要吸附在Co及其近邻六元环的顶位,吸附结构的电荷转移表明掺杂原子Co对BN衬底的气敏特性有较好的调制作用;2)在Co-BN表面吸附的O_2和CO较易被活化,表明Co-BN可能是一种对CO氧化有较好催化活性的新型催化材料.

The first principles study is performed to explore the adsorption properties of gas molecules （O2, H2, NO, CO, CO2, SO2, H2S, H2O） on the surface of Co doped monolayer BN （Co-BN）.The geometrical structures, adsorption energies and charge transfer of the small molecules were revealed systematically. The results show that： 1） The gas molecules, such as CO prefer to be adsorbed on the top site of Co atom or the six-membered ring nearest neighbor to Co. The charge transfer analysis of the most stable adsorption structures showed that the doped Co atom has a good influence on the gas sensing properties of BN substrate. 2） The adsorbed O2 and CO can be activated easily, which indicates that Co-BN may be new type of catalytic material with a good catalytic activity for CO oxidation.