Effects of Al Content and Synthesis Temperature on Al-Substituted Fe Oxides: Crystal Properties and Fe(III) Bioaccessibility

摘要: Four series of Al-substituted Fe oxides with different Al con- tents were synthesized under temperatures and characterized to study the effects substitution on crystal properties bioacces- sibility oxides. The UV-visible diffuse-reflectance spectra their first derivatives showed that color changes from red white associ- ated thevisible absorbance X-ray dif- fractionresultsshowedthatthepresenceofAlinFeoxidescouldhinder formation maghemite hematite in additionto transforma- tion during sintering. Brunauer-Emmett- Teller surface areas increased increasing content decreasing sintering temperatures. Fourier transform infra- results gibbsite formed high contents. structure, crystallinity, area heavily depended temperature. hydroxylamine-reducible Fe(III) also investigated. hydroxylamine- reducible fortheFeoxideswithahighdegreeof crystallizationwhensynthe- sized at higher (>300°C) but decreased for a low temperature (180°C). effect was attrib- utable structures—all whichcan provide detailed information neededto under- stand iron reactivity natural soils or sediments.