{"title":"Investigating the vital influence of multi-factor synergies on the formation of nitrate on the surface of nano MgO particles†","authors":"Lihui Han, Chaonan Qi, Jian Tian, Tong Lan, Qian Xiao, Shuiyuan Cheng, Wei Wei, Haiyan Wang, Jinghua Guo and Aihua Zheng","doi":"10.1039/D4EN00316K","DOIUrl":null,"url":null,"abstract":"<p >With the rapidly increasing number of motor vehicles in megacities in recent years, nitrate has become a crucial component in atmospheric fine particulate matter, which has significant impacts on the formation of haze. In this study, a photochemical smog chamber was used to investigate the effect of atmospheric pollutants such as O<small><sub>3</sub></small>, NH<small><sub>3</sub></small> and SO<small><sub>2</sub></small> on the heterogeneous formation of nitrate on the surface of nano MgO particles in the two reaction systems of NO<small><sub>2</sub></small>–MgO-dark and NO<small><sub>2</sub></small>–MgO-<em>hν</em> and their related formation mechanisms. In the dark, similar to nighttime, O<small><sub>3</sub></small>, NH<small><sub>3</sub></small> and SO<small><sub>2</sub></small> played a key role in promoting the heterogeneous formation of nitrate on the surface of nano MgO particles, following the order O<small><sub>3</sub></small> > SO<small><sub>2</sub></small> > NH<small><sub>3</sub></small>. It was noted that the synergy between O<small><sub>3</sub></small> and SO<small><sub>2</sub></small> or NH<small><sub>3</sub></small> was more favorable for the heterogeneous formation of nitrate. Besides, the heterogeneous formation of nitrite was greatly impacted by NH<small><sub>3</sub></small> and SO<small><sub>2</sub></small>. Alternatively, under UV light, similar to daytime, the synergy between UV light and O<small><sub>3</sub></small> greatly promoted the heterogeneous formation of nitrate, whereas NH<small><sub>3</sub></small> and SO<small><sub>2</sub></small> exerted an inhibitory effect. The mechanisms for the heterogeneous formation of nitrate on the surface of nano MgO particles were strongly affected by UV light, O<small><sub>3</sub></small>, NH<small><sub>3</sub></small> and SO<small><sub>2</sub></small>, presenting different reaction mechanisms. The synergistic effects of O<small><sub>3</sub></small>, NH<small><sub>3</sub></small> and SO<small><sub>2</sub></small> on the heterogeneous formation of nitrate at nighttime were obviously higher than that of UV light, O<small><sub>3</sub></small>, NH<small><sub>3</sub></small> and SO<small><sub>2</sub></small> at daytime, implying that nighttime is more favorable for the heterogeneous formation of nitrate.</p>","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":null,"pages":null},"PeriodicalIF":5.8000,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental Science: Nano","FirstCategoryId":"6","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2024/en/d4en00316k","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
With the rapidly increasing number of motor vehicles in megacities in recent years, nitrate has become a crucial component in atmospheric fine particulate matter, which has significant impacts on the formation of haze. In this study, a photochemical smog chamber was used to investigate the effect of atmospheric pollutants such as O3, NH3 and SO2 on the heterogeneous formation of nitrate on the surface of nano MgO particles in the two reaction systems of NO2–MgO-dark and NO2–MgO-hν and their related formation mechanisms. In the dark, similar to nighttime, O3, NH3 and SO2 played a key role in promoting the heterogeneous formation of nitrate on the surface of nano MgO particles, following the order O3 > SO2 > NH3. It was noted that the synergy between O3 and SO2 or NH3 was more favorable for the heterogeneous formation of nitrate. Besides, the heterogeneous formation of nitrite was greatly impacted by NH3 and SO2. Alternatively, under UV light, similar to daytime, the synergy between UV light and O3 greatly promoted the heterogeneous formation of nitrate, whereas NH3 and SO2 exerted an inhibitory effect. The mechanisms for the heterogeneous formation of nitrate on the surface of nano MgO particles were strongly affected by UV light, O3, NH3 and SO2, presenting different reaction mechanisms. The synergistic effects of O3, NH3 and SO2 on the heterogeneous formation of nitrate at nighttime were obviously higher than that of UV light, O3, NH3 and SO2 at daytime, implying that nighttime is more favorable for the heterogeneous formation of nitrate.
期刊介绍:
Environmental Science: Nano serves as a comprehensive and high-impact peer-reviewed source of information on the design and demonstration of engineered nanomaterials for environment-based applications. It also covers the interactions between engineered, natural, and incidental nanomaterials with biological and environmental systems. This scope includes, but is not limited to, the following topic areas:
Novel nanomaterial-based applications for water, air, soil, food, and energy sustainability
Nanomaterial interactions with biological systems and nanotoxicology
Environmental fate, reactivity, and transformations of nanoscale materials
Nanoscale processes in the environment
Sustainable nanotechnology including rational nanomaterial design, life cycle assessment, risk/benefit analysis