MnO2-Al2O3 （MOAO） binary nanocomposite with a 1：3 MnO2 to Al2O3 molar ratio was synthesized by impregnation technique using mesoporous alumina （MA） precursor. The MOAO product consisted of MA and amorphous MnO2. ...MnO2-Al2O3 （MOAO） binary nanocomposite with a 1：3 MnO2 to Al2O3 molar ratio was synthesized by impregnation technique using mesoporous alumina （MA） precursor. The MOAO product consisted of MA and amorphous MnO2. The manganese valence in MOAO was ＋4, indicative of MnO2 being coated on the surface of MA during the impregnation process. MOAO had a large specific surface area （385.266 m^2/g） and wormhole-like mesoporous structure. The average pore size, which could be precisely controlled over the range of 3.4-4.1 nm. The optimum removal of fluoride was obtained when the initial pH was in the range of 4-10. The defluorination efficiency of MOAO was far superior to that of MA when the initial fluoride concentration exceeded 40 mg/L. The large surface area and bimodal porous structure of MOAO after coating MnO2 may be responsible for the high removal efficiency in the defluorination process.展开更多
文摘MnO2-Al2O3 （MOAO） binary nanocomposite with a 1：3 MnO2 to Al2O3 molar ratio was synthesized by impregnation technique using mesoporous alumina （MA） precursor. The MOAO product consisted of MA and amorphous MnO2. The manganese valence in MOAO was ＋4, indicative of MnO2 being coated on the surface of MA during the impregnation process. MOAO had a large specific surface area （385.266 m^2/g） and wormhole-like mesoporous structure. The average pore size, which could be precisely controlled over the range of 3.4-4.1 nm. The optimum removal of fluoride was obtained when the initial pH was in the range of 4-10. The defluorination efficiency of MOAO was far superior to that of MA when the initial fluoride concentration exceeded 40 mg/L. The large surface area and bimodal porous structure of MOAO after coating MnO2 may be responsible for the high removal efficiency in the defluorination process.
