Porous texture in hematite derived from goethite: Mechanism of thermal decomposition of geothite

Optimization of the Dehydration Temperature of Goethite to Control Pore Morphology

“…2. Similar slit-like pore generation was reported by Naono et al 29,31) and Walter et al 25) The observed change in the slit width is in good agreement with the pore size distribution shown in Fig. 5(a).…”

“…Numerous articles related to study of the goethite-hematite phase transformation by thermogravimetric analysis, [21][22][23][24][25][26] pore morphology observation, 22,[27][28][29][30][31][32] crystal structure analysis, 22,23,29,[31][32][33][34] and using substitutional elements such as Al and Ti [35][36][37] have been published. When goethite transforms to hematite by thermal decomposition at lower temperature (below 300°C), uniform slit-shaped micropores are formed in the hematite.…”

Heterogeneous oxidation of Fe(II) on iron oxides in aqueous systems: Identification and controls of Fe(III) product formation

“…Finally, the role of hematite micropores in Fe(II) sorption and oxidation requires further attention. While our BET surface area measurements did not include micropore analysis, there is a possibility of sub-nanometer sized pores existing on hematite surfaces (particularly for hydrothermally-synthesized hematite from goethite, i.e., the hexagons (Naono et al, 1987)), providing additional surface area, and lessening the number of monolayer coverages. A clearer conceptual model can be made by combining our observations of secondary mineral formation with additional X-ray and infra-red based surface spectroscopic techniques as well as surface porosity analysis.…”

Anisotropic X-ray peak broadening and twin formation in hematite derived from natural and synthetic goethite

“…[2][3][4][5] The pores serve as diffusion paths for the water during the reaction. Dehydration at higher temperatures leads to a decrease in the regularity of the pore system.…”