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DOI	10.5194/acp-22-11347-2022
	The positive effect of formaldehyde on the photocatalytic renoxitication of nitrate on TiO2 particles
	Liu, Yuhan; Wang, Xuejiao; Shang, Jing; Xu, Weiwei; Sheng, Mengshuang; Ye, Chunxiang
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	11347
结束页码	11358
卷号	22 期号:17 页码:12
英文摘要	Renoxification is the process of recycling NO3-/HNO3 into NOx under illumination and is mostly ascribed to the photolysis of nitrate. TiO2, a typical mineral dust component, is able to play a photocatalytic role in the renoxification process due to the formation of NO3 radicals; we define this process as photocatalytic renoxification. Formaldehyde (HCHO), the most abundant carbonyl compound in the atmosphere, may participate in the renoxification of nitrate-doped TiO2 particles. In this study, we established a 400 L environmental chamber reaction system capable of controlling 0.8 %-70 % relative humidity at 293 K with the presence of 1 or 9 ppm HCHO and 4 wt % nitrate-doped TiO2. The direct photolyses of both nitrate and NO3 radicals were excluded by adjusting the illumination wavelength so as to explore the effect of HCHO on the photocatalytic renoxification. It was found that NOx concentrations can reach up to more than 100 ppb for nitrate-doped TiO2 particles, while almost no NOx was generated in the absence of HCHO. Nitrate type, relative humidity and HCHO concentration were found to influence NOx release. It was suggested that substantial amounts of NOx were produced via the NO3--NO3 center dot-HNO3-NOx pathway, where TiO2 worked for converting NO3- to NO3 center dot, that HCHO participated in the transformation of NO3 center dot to HNO3 through hydrogen abstraction, and that HNO3 photolysis answered for mass NOx release. So, HCHO played a significant role in this photocatalytic renoxification process. These results were found based on simplified mimics for atmospheric mineral dust under specific experimental conditions, which might deviate from the real situation but illustrated the potential of HCHO to influence nitrate renoxification in the atmosphere. Our proposed reaction mechanism by which HCHO promotes photocatalytic renoxification is helpful for deeply understanding atmospheric photochemical processes and nitrogen cycling and could be considered for better fitting atmospheric model simulations with field observations in some specific scenarios.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000850335900001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/272991
作者单位	Peking University
推荐引用方式 GB/T 7714	Liu, Yuhan,Wang, Xuejiao,Shang, Jing,et al. The positive effect of formaldehyde on the photocatalytic renoxitication of nitrate on TiO2 particles[J],2022,22(17):12.
APA	Liu, Yuhan,Wang, Xuejiao,Shang, Jing,Xu, Weiwei,Sheng, Mengshuang,&Ye, Chunxiang.(2022).The positive effect of formaldehyde on the photocatalytic renoxitication of nitrate on TiO2 particles.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(17),12.
MLA	Liu, Yuhan,et al."The positive effect of formaldehyde on the photocatalytic renoxitication of nitrate on TiO2 particles".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.17(2022):12.