In this work, chemical and structural properties of various biochars were analyzed and compared with those from a highly stable anthropic soil, Terra Preta de Índio (TPI). TPI is believed to be responsible for the fertility of Amazonian soils and their stability; therefore, the production of a synthetic TPI would be of great interest for agricultural applications. Biochar produced from different raw biomasses were comprehensively characterized and, based on the obtained results, a preliminary study was performed testing three different routes of chemical activation using nitric acid, phosphoric acid, and potassium hydroxide as activating agents. After chemical activations, metal contents in the biochars decreased, as expected, and high degrees of carbonization were observed. In the case of the activation performed with HNO, intense signals related to carboxylic groups in TG-MS analysis and in potentiometric titrations point out to a highly oxygenated biochar. Structural analysis showed that activations generated point defects in sp-carbon structures of biochar, with the material obtained after KOH activation showing a high surface area (569 m g), an important feature for the use as soil amendment.
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http://dx.doi.org/10.1016/j.jenvman.2020.111685 | DOI Listing |
Spectrochim Acta A Mol Biomol Spectrosc
December 2024
School of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Chemical Reaction Engineering, Laboratory of New Energy & New Function Materials, Yanan University, Yan'an 716000, China.
Elemental analysis, infrared spectroscopy, and X-ray single crystal diffraction indicated that a novel metal-organic framework (Tb-MOF) designated as 0.5n[Hbpy]·[Tb(dpa)(HO)]·4nHO was synthesized successfully, (where Hdpa = 5-(3, 4-dicarboxy- phenoxy) isophenic acid, bpy = protonated 4,4'-bipyridine). Tb-MOF adopts a 3D network structure based on Tb ions and the (dpa) ligand through µ: η, η, η, η binding modes.
View Article and Find Full Text PDFSci Rep
January 2025
School of Information Technology, Jiangsu Open University, Nanjing, 210017, China.
Because of its dimensional characteristics, two-dimensional (2D) materials exhibit many special properties. The key to researching their features is to prepare high-quality larger-area monolayer 2D materials. Metal-assisted mechanical exfoliation method offers the possibility.
View Article and Find Full Text PDFNat Commun
January 2025
Center for High Pressure Science and Technology Advanced Research, Beijing, 100093, China.
Due to the sulfur's atoms' propensity to form molecules and/or polymeric chains of various sizes and configuration, elemental sulfur possesses more allotropes and polymorphs than any other element at ambient conditions. This variability of the starting building blocks is partially responsible for its rich and fascinating phase diagram, with pressure and temperature changing the states of sulfur from insulating molecular rings and chains to semiconducting low- and high-density amorphous configurations to incommensurate superconducting metallic atomic phase. Here, using a fast compression technique, we demonstrate that the rapid pressurisation of liquid sulfur can effectively break the molecular ring structure, forming a glassy polymeric state of pure-chain molecules (Am-S).
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January 2025
Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK. Electronic address:
In a recent issue of Nature Methods, Pfeil-Gardiner et al. (2024) combine electron energy-loss spectroscopy and single-particle cryoelectron microscopy to allow the spatially resolved imaging of the elemental composition of macromolecules.
View Article and Find Full Text PDFAnal Chem
January 2025
Separation Science Group, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281 S4bis, B-9000 Ghent, Belgium.
Addressing the global challenge of ensuring access to safe drinking water, especially in developing countries, demands cost-effective, eco-friendly, and readily available technologies. The persistence, toxicity, and bioaccumulation potential of organic pollutants arising from various human activities pose substantial hurdles. While high-performance liquid chromatography coupled with high-resolution mass spectrometry (HPLC-HRMS) is a widely utilized technique for identifying pollutants in water, the multitude of structures for a single elemental composition complicates structural identification.
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