Work

Redox-state-dependent adsorption of arsenic and antimony on hydrothermally synthesized mesoporous boehmite (γ-AlOOH): mechanistic insights from synchrotron-based spectroscopy

Year: 2026

Type: article

Abstract: Hierarchical mesoporous boehmite (γ-AlOOH) was synthesized via a one-pot hydrothermal method across a wide range of pH, temperature, aging time, and aluminum concentrations to identify optimal formation conditions and elucidate arsenic and antimony adsorption behavior. The optimized sample, which was obtained at pH 4, 150 °C, 24 h aging, and [Al] = 0.1 M, exhibited a plate-stacked spherical morphology with a high surface area (149 m2/g) and large pore volume (0.42 cm3/g). Batch adsorption experiments showed sorption capacities of 66 mg/g for As(III) at pH 9, 38 mg/g for As(V) at pH 5, and 55 mg/g for Sb(V) at pH 5, whereas Sb(III) displayed the lowest uptake (13 mg/g at pH 5). Spectroscopic analyses (synchrotron X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared) indicated inner-sphere complexation with surface hydroxyls for As(III, V) and Sb(V), whereas Sb(III) bound mainly through weaker outer-sphere interactions, consistent with its negligible Al coordination. Both As(III) and As(V) formed bidentate binuclear corner-sharing complexes on the boehmite surface, whereas Sb(V) adopted both bidentate edge-sharing and corner-sharing geometries. These results show that metal(loid) adsorption strongly depends on anion redox state and highlight that the optimal removal of As and Sb requires solution conditions tailored to each species. Overall, this study provides insights into redox-dependent adsorption and demonstrates that hydrothermally engineered boehmite is a robust, high-capacity adsorbent for metalloid remediation in complex aqueous systems.

Source: Journal of Colloid and Interface Science

DOI: 10.1016/j.jcis.2026.140517

Authors: Sue A Kang, Seon Yong Lee, Chul-Min Chon, Bongsu Chang, Ji-Hyun Park, Young Jae Lee

Institutions: Korea University, Korea Institute of Geoscience and Mineral Resources

Language: English

Topic: Arsenic contamination and mitigation

Subfield: Environmental Chemistry

Field: Environmental Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,470