Chemical Analysis and Molecular Models for Calcium鈥揙xygen鈥揅arbon Interactions in Black Carbon Found in Fertile Amazonian Anthrosoils

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• 作者：Braulio S. Archanjo ; Joyce R. Araujo ; Alexander M. Silva ; Rodrigo B. Capaz ; Newton P. S. Falc茫o ; Ado Jorio ; Carlos A. Achete
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：July 1, 2014
• 年：2014
• 卷：48
• 期：13
• 页码：7445-7452
• 全文大小：458K
• ISSN：1520-5851

文摘

Carbon particles containing mineral matter promote soil fertility, helping it to overcome the rather unfavorable climate conditions of the humid tropics. Intriguing examples are the Amazonian Dark Earths, anthropogenic soils also known as 鈥淭erra Preta de 脥ndio鈥欌€?(TPI), in which chemical recalcitrance and stable carbon with millenary mean residence times have been observed. Recently, the presence of calcium and oxygen within TPI-carbon nanoparticles at the nano- and mesoscale ranges has been demonstrated. In this work, we combine density functional theory calculations, scanning transmission electron microscopy, energy dispersive X-ray spectroscopy, Fourier transformed infrared spectroscopy, and high resolution X-ray photoelectron spectroscopy of TPI-carbons to elucidate the chemical arrangements of calcium鈥搊xygen鈥揷arbon groups at the molecular level in TPI. The molecular models are based on graphene oxide nanostructures in which calcium cations are strongly adsorbed at the oxide sites. The application of material science techniques to the field of soil science facilitates a new level of understanding, providing insights into the structure and functionality of recalcitrant carbon in soil and its implications for food production and climate change.