Fe 2 O 3 /Al 2 O 3 microboxes for efficient removal of heavy metal ions

Iron oxide/aluminum oxide microboxes (Fe 2 O 3 /Al 2 O 3 MBs) with cubic structures (1 ± 0.09 μm) possessing large specific surface area (208.3 m 2 g −1 ) and high adsorption capacity (216 mg g −1 ) were prepared and utilized for the removal of mercury (Hg 2+ ) (100 ppm) from various samples, including tap water, lake water and tomato juice, with efficiencies of 98.2 ± 0.4, 98.5 ± 0.3 and 97.1 ± 0.5%, respectively. The Fe 2 O 3 /Al 2 O 3 MBs are stable, allowing the adsorbed metal species to be removed from their surfaces with 2 M HCl. The Fe 2 O 3 /Al 2 O 3 MBs can be reused up to five times after being treated with 2 M HCl. Furthermore, the Fe 2 O 3 /Al 2 O 3 MBs are efficient adsorbents for the removal of four metal ions such as Hg 2+ , cadmium (Cd 2+ ), copper (Cu 2+ ), and lead (Pb 2+ ) ions from soil samples, mainly because of a synergetic effect provided by the two metal oxides and high surface area. This low-cost, effective, and stable Fe 2 O 3 /Al 2 O 3 adsorbent holds great potential for the removal of Hg 2+ and other heavy metal ions from contaminated sources such as water and soil.