Mesostructured iron oxides（MIOs） were nanocasted from a plugged hexagonal templated silica（PHTS） with a Brunauer-Emmett-Teller（BET） surface area of 694 m 2 /g.Results of X-ray diffraction（XRD）,transmission electron microscopy（TEM） and N 2 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 °C） with a BET surface area of 82 m^ 2 /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.
