Density functional theory study on the mechanism of CO sensing on Cu₂O (1 1 1) surface: Influence of the pre-adsorbed oxygen atom

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• 作者：Yaoyao Shen ; Feng Hui Tian ; Shougang Chen ; Zhenqing Ma ; Linghuan Zhao ; Xiangfeng Jia
• 关键词：CO adsorption ; Cu2O (1  ; 1  ; 1) surface ; Pre-adsorbed O atom ; Sensing ; DFT
• 刊名：Applied Surface Science
• 出版年：1 January, 2014
• 年：2014
• 卷：288
• 期：Complete
• 页码：452-457
• 全文大小：1752 K

文摘

The adsorption of CO molecule on the Cu₂O (1 1 1) surface with or without pre-adsorbed oxygen atom (O_ad) has been investigated using density functional theory calculation. Calculations show that the adsorption of O_ad causes obvious changes in the electronic structure and charge distribution of Cu₂O with a charge transfer of 0.48 e from substrate to O_ad. On the perfect Cu₂O (1 1 1) surface, the one-fold coordinated copper (Cu_1c) atom is the most favorable site for the adsorption of CO with a charge transfer of 0.414 e from CO molecule to substrate. Moreover, it is found that the adsorption of CO on the O pre-adsorbed Cu₂O (1 1 1) surface is strengthened. The adsorbed CO molecule tends to interact with O_ad atom and release the electrons trapped by the oxygen adatom back to the substrate, resulting in a significant charge variation (0.619 e). All these findings indicate that Cu₂O would be a good candidate for the detection of CO gas.