Hollow rod assembly of Fe-MnO2 nanosheets prepared by in situ redox etching for the ultra-fast removal of antimony

Antimony pollution is of increasing concern and designing efficient adsorbents to solve this problem of antimony removal from wastewater has shown significance in both science and practical application. In this work, a Fe-Mn bimetal oxides composite is fabricated with an in situ redox etching-growth strategy. The obtained adsorbent is made of lattice-widening MnO2 nanosheets, which are doped with Fe ion homogeneously. The nanosheets stack to a hollow sea cucumber-like structure, which promotes the facile adsorption of Sb with both fast and large capacity adsorption. It can reach the adsorption equilibrium in 5 min and has a high capacity of 347.2 mg/g. The excellent adsorption properties benefit from the special crystal structure， and the antimony is closely connected to the adsorbent by binding modes of inner-sphere complexation, redox, and hydrogen bonding.