Electrocatalytic nitrate reduction using iron single atoms for sustainable ammonium supplies to increase rice yield

• 成果类型: Article
• 署名作者: Liu, Chunlei; Ma, Jingchen; Wang, Manting; Xu, Jingru; Zhu, Chao; Zhu, Guibing
• 署名单位: Chinese Academy of Sciences; Research Center for Eco-Environmental Sciences (RCEES), CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Shaanxi University of Science & Technology
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12025
• DOI: 10.1073/pnas.2408187121
• 发表日期: 2024-12-10
• 关键词: nitrogen; oxidation; plant

摘要

Increasing food production and ensuring drinking water safety have always been a focus of attention, especially for people in underdeveloped regions of the world. Traditional excessive fertilizer applications have increased crop yield but also caused groundwater nitrate pollution. Agricultural irrigating water is an important reservoir for nitrogen (N) (e.g., nitrate) accumulation after fertilization. Ammonium (NH4+-N) is a more readily absorbed N form by rice than nitrate (NO3--N). In this study, we proposed a strategy using iron single- atom catalysts (Fe- SAC) to selectively reduce NO3--N to NH4+-N from the real paddy field irrigating water to provide sustainable NH4+-N supplies for rice uptakes, thereby highlighting decreasing N fertilizer applications and mitigating NO3--N pollution. Then, we constructed a solar- energy- driven electrochemical reactor for NO3--N reduction, with the Fe single atom as the core catalyst, and achieved an average NH4+-N selectivity of 80.2 +/- 2.6% with no additional energy input. Sustainable NH4+-N supplies resulted in a 30.4 % increase in the 100- grain weight of the cultivated rice and a 50% decrease of fertilizer application than those of the fertilization group in the pot experiment, which were one of the best values ever reported. Furthermore, the 15 N isotope tracing results indicated a N use efficiency (NUE) from 15 NO 3 -- N of 71.2 +/- 3.2%. Sustainable NH4+-N supplies played a key role in promoting rice root development which contributed to the high NUE. Our study shares unique insights in increasing grain yield, reducing fertilizer applications, and preventing nitrate leaching into groundwater.