Surface Characterization of γ‐Al₂O₃ Powders and Their Co²⁺ Adsorption Properties

Abstract

The relationship between structural and surface properties of γ‐alumina prepared by various methods has been studied, and the adsorption ability of the powders for cobalt ions from aqueous solution is presented, based on the results of X‐ray diffraction, specific surface area, scanning electron microscopy, and surface hydroxyl group concentration of the resulting products. Results show that γ‐alumina obtained by solution‐combustion method (specific surface area: 232.9 m2/g; morphology: lamellar and mesoporous; hydroxyl group content: 0.24 meq OH−/g) exhibited the best Co2+ adsorption. Furthermore, the synthesis of γ‐alumina is highly helpful to study various structural and surface properties of this material.

Influence of p-n junction mechanism and alumina overlayer on the photocatalytic performance of TiO2 nanotubes

“…The modification of the host TiO 2 is also achieved by coupling with non-semiconducting charge transfer catalysts (CTC), such as Al 2 O 3 , or SiO 2 that have the ability to trap photogenerated electrons, thus slowing down carrier recombination [15][16][17]. Al 2 O 3 has the additional advantage of high adsorption ability and has energy levels that aid charge transfer [18][19][20]. Recently, there were reports of Al 2 O 3 /TiO 2 nano films [21,22] and Al 2 O 3 /TiO 2 composite nanoparticles [23,24] with significantly enhanced photocatalytic activity.…”

Evaluation of the Mn(II) adsorption potential of SiO2 obtained by different wet chemical methods

“…Metals such as cobalt (Co), copper (Cu), manganese (Mn), and zinc (Zn) are beneficial to live beings because they participate in vital processes in their bodies, but in high quantities, they become toxic and contaminate the environment . The presence of manganese in high concentrations in aquatic environments, usually from industrial processes such as mining and ore processing, causes inorganic pollution due to the fact that the metal is not biodegradable, presents toxicity and can accumulate in humans and animals, causing adverse reactions .…”

“…Therefore, the removal of such metals from polluted water has attracted considerable attention . Adsorption studies of metals have been increasingly emphasized in the decontamination of effluents containing toxic metals, using various materials as adsorbents, such as activated carbon, sawdust of various origins, natural zeolite, and oxides of different types, with emphasis on SiO 2 . Due to its high porosity and specific area, SiO 2 (silica) is widely applied in studies of toxic metal removal in the treatment of contaminated water.…”