Crystal Face Distributions and Surface Site Densities of Two Synthetic Goethites: Implications for Adsorption Capacities as a Function of Particle Size
| Autor: | Paul A. Midgley, Milton Villacís-García, Mario Villalobos, J.S. Barnard, Anna Goodridge, Maria Varela, Rodolfo Zanella, Rowan K. Leary, Kenneth J. T. Livi |
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| Rok vydání: | 2017 |
| Předmět: |
Goethite
Materials science Analytical chemistry 02 engineering and technology Surfaces and Interfaces Surface finish 010501 environmental sciences 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Atomic units Crystal Crystallography Adsorption visual_art Electrochemistry visual_art.visual_art_medium Surface roughness General Materials Science Particle size 0210 nano-technology High-resolution transmission electron microscopy Spectroscopy 0105 earth and related environmental sciences |
| Zdroj: | Langmuir. 33:8924-8932 |
| ISSN: | 1520-5827 0743-7463 |
| DOI: | 10.1021/acs.langmuir.7b01814 |
| Popis: | Two synthetic goethites of varying crystal sizes distributions were analyzed by BET, conventional TEM, cryo-TEM, atomic resolution STEM and HRTEM, and electron tomography in order to determine the effects of crystal size, shape, and atomic scale surface roughness on their adsorption capacities. The two samples were determined by BET to have very different site densities based on CrVI adsorption experiments. Model specific surfaces areas generated from TEM observations showed that, based on size and shape, there should be little difference in their adsorption capacities. Electron tomography revealed that both samples crystallized with an asymmetric {101} tablet habit. STEM and HRTEM images showed a significant increase in atomic-scale surface roughness of the larger goethite. This difference in roughness was quantified based on measurements of relative abundances of crystal faces {101} and {201}for the two goethites, and a reactive surface site density was calculated for each goethite. Singly-coordinated s... |
| Databáze: | OpenAIRE |
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