Synthesis of Hematite (α-Fe2O3) Nanostructures by Thermal Oxidation of Iron Sheet for Cr (VI) Adsorption
| Autor: | Anfernee B. Silvestre, Mikko James C. Bongar, Mary Donnabelle L. Balela, Christian Laurence E. Aquino |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Thermal oxidation
Materials science Nanostructure Mechanical Engineering 02 engineering and technology Hematite 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Adsorption Chemical engineering Mechanics of Materials visual_art visual_art.visual_art_medium General Materials Science 0210 nano-technology |
| Zdroj: | Key Engineering Materials. 775:395-401 |
| ISSN: | 1662-9795 |
| DOI: | 10.4028/www.scientific.net/kem.775.395 |
| Popis: | In this study, hematite (α-Fe2O3) nanostructures were synthesized via thermal oxidation of Fe sheet in dry air and in water vapor. SEM images show nanoblades and nanowires growing on the surface of the sheet. Samples synthesized in water vapor generally produced larger nanostructures while samples oxidized in higher temperatures formed taller and slender nanostructures. The α-Fe2O3nanostructures were used as adsorbent for Cr (VI) in acidic medium. Chromium removal was highest with the samples synthesized at 650°C in water vapor with 95% efficiency. Kinetic and thermodynamic studies revealed that the adsorption process strongly followed pseudo-second order kinetics model and is endothermic. The process also follows the Langmuir adsorption isotherm model, suggesting that the process is described by homogeneous, monolayer adsorption. Adsorption of Cr (VI) onto hematite may be attributed to the electrostatic reaction between the positively charged hematite adsorbent and negative chromium ion. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|