Acta Chimica Sinica ›› 2023, Vol. 81 ›› Issue (11): 1493-1499.DOI: 10.6023/A23060312 Previous Articles     Next Articles

Article

铜掺杂与氮化碳复合氧化锌材料结构和二氧化氮气体传感性质的密度泛函理论计算

王娟a, 肖华敏a, 谢丁a, 郭元茹b,*(), 潘清江a,*()   

  1. a 黑龙江大学功能无机材料化学教育部重点实验室 化学化工与材料学院 哈尔滨 150080
    b 东北林业大学生物质材料科学与技术教育部重点实验室 材料科学与工程学院 哈尔滨 150040
  • 投稿日期:2023-06-28 发布日期:2023-08-17
  • 基金资助:
    国家自然科学基金(22276046); 国家自然科学基金(U2167219); 中央支持地方高校改革发展资金人才培养项目(骨干人才2021)

Density Functional Theory Study of Structures of Copper-doped and Graphitic Carbon Nitride-combined Zinc Oxides and Their Boosted Nitrogen Dioxide-sensing Performance

Juan Wanga, Huamin Xiaoa, Ding Xiea, Yuanru Guob(), Qingjiang Pana()   

  1. a Key Laboratory of Functional Inorganic Material Chemistry of Education Ministry, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, China
    b Key Laboratory of Bio-based Material Science & Technology of Education Ministry, College of Material Science and Engineering, Northeast Forestry University, Harbin 150040, China
  • Received:2023-06-28 Published:2023-08-17
  • Contact: *E-mail: guoyr@nefu.edu.cn; panqingjiang@hlju.edu.cn
  • Supported by:
    National Natural Science Foundation of China(22276046); National Natural Science Foundation of China(U2167219); Fund of the Reformation and Development of Local Universities out of the Central Government(骨干人才2021)

Of numerous environmental problems, the air pollution caused by toxic nitrogen dioxide has become more and more serious. Its timing detection is of utmost importance but challenging. It is known that NO2 sensors fabricated by zinc oxide-derived materials suffer some issues. And thus synthetic strategies such as doping and combining have been developed to improve sensitive performance and modify operation condition. However, the relevant sensing reaction mechanism still remains unclear; moreover, the experimentally structural characterizations on sensitive materials (SMs) and reaction intermediates are rather difficult at the atomic level, which turn much worse for the doped and combined SMs. In the work, density functional theory calculations have been exploited to examine copper-doped zinc oxide (marked as ZOC) and its composites ZOC/CN and ZOC/Gr. CN and Gr are short for 2D materials, graphitic carbon nitride (g-C3N4) and graphene, respectively. The local structures have been accessible for these SMs and their intermediates along the reaction pathway. It is shown that ZOC bears the Cu-Zn heterobimetallic adsorption active sites, which hold NO2 via Cu/Zn-O dative bonds. The introduction of copper increases metal contribution to high-lying occupied molecular orbitals (MOs). Major NO2ZOC donation and minor back-donation interactions have been recognized by charge decomposition analyses in terms of fragment MOs. Consequently, its adsorption free energy towards NO2 is strengthened by 0.27 eV relative to pristine ZnO. These well interpret the experimental findings that the copper-doped zinc oxide has much faster response time. Further combination with g-C3N4 enhances the NO2-sensing performance, which turns out to be the best SM candidate. Exemplarily, ZOC/CN shows the most negative NO2 adsorption energy (–0.31 eV), very small uphill energy for the rate-determining step (0.27 eV) and modest formation energy of nitrate (–1.06 eV). With these, the SM not only responses NO2 rapidly but also desorbs nitrate at mild experimental condition. In brief, the theoretical study allows to deeply understand synthetic strategies that can improve sensing performance, and helps to search out novel sensitive materials.

Key words: ZnO-based sensitive material, metal-doping and 2D material combination, Cu-Zn heterobimetallic active sites, thermodynamics and interfacial property, sensing mechanism, DFT calculations