Synthesis of Mesostructured Iron Oxides with Potential As(V) Adsorption Application

Mesostructured iron oxides(MIOs) were nanocasted from a plugged hexagonal templated silica(PHTS) with a Brunauer-Emmett-Teller(BET) surface area of 694 m²/g. Results of X-ray diffraction(XRD), transmission electron microscopy(TEM) and N₂ adsorption-desorption suggest that the nanocasted MIOs are synthetic hematite(α-Fe₂O₃) with a wormhole-like mesoporous network. As(V) adsorption test shows that the selected MIO—MIO-500(calcinated at 500℃) with a BET surface area of 82 m²/g has a maximum adsorption capacity of 5.39 mg/g for As(V), which is 2.5 times as large as that of natural hematite adsorbent. The study suggests that MIOs could be potentially used as the adsorbent of As(V) in wastewater.