Zhao Jingjing, Zhang Xuejiao, Zhao Qing, Yu Xue-Feng, Zhang Siyu, Xing Baoshan
Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Shenyang Institute of Applied Ecology, University of Chinese Academy of Sciences, Beijing 100049, China.
Nanomaterials (Basel). 2022 Jun 10;12(12):2011. doi: 10.3390/nano12122011.
Air pollution caused by acid gases (NO, SO) or greenhouse gases (CO) is an urgent environmental problem. Two-dimensional nanomaterials exhibit exciting application potential in air pollution control, among which layered black phosphorus (LBP) has superior performance and is environmentally friendly. However, the current interaction mechanism of LBP with hazardous gases is contradictory to experimental observations, largely impeding development of LBP-based air pollution control nanotechnologies. Here, interaction mechanisms between LBP and hazardous gases are unveiled based on density functional theory and experiments. Results show that NO is different from other gases, as it can react with unsaturated defects of LBP, resulting in oxidation of LBP and reduction of NO. Computational results indicate that the redox is initiated by p orbital hybridization between one oxygen atom of NO and the phosphorus atom carrying a dangling single electron in a defect's center. For NO, the interaction mechanism is chemisorption on unsaturated LBP defects, whereas for SO, NH, CO or CO, the interaction is dominated by van der Waals forces (57-82% of the total interaction). Experiments confirmed that NO can oxidize LBP, yet other gases such as CO cannot. This study provides mechanistic understanding in advance for developing novel nanotechnologies for selectively monitoring or treating gas pollutants containing NO.
由酸性气体（NO、SO）或温室气体（CO）造成的空气污染是一个紧迫的环境问题。二维纳米材料在空气污染控制方面展现出令人兴奋的应用潜力，其中层状黑磷（LBP）具有卓越性能且环保。然而，目前LBP与有害气体的相互作用机制与实验观测结果相矛盾，这在很大程度上阻碍了基于LBP的空气污染控制纳米技术的发展。在此，基于密度泛函理论和实验揭示了LBP与有害气体之间的相互作用机制。结果表明，NO与其他气体不同，它能与LBP的不饱和缺陷发生反应，导致LBP被氧化而NO被还原。计算结果表明，这种氧化还原反应是由NO中的一个氧原子与缺陷中心携带单悬电子的磷原子之间的p轨道杂化引发的。对于NO，其相互作用机制是化学吸附在不饱和的LBP缺陷上，而对于SO、NH、CO或CO，相互作用主要由范德华力主导（占总相互作用的57 - 82%）。实验证实NO能氧化LBP，但CO等其他气体则不能。这项研究为开发用于选择性监测或处理含NO气体污染物的新型纳米技术提前提供了机理认识。
